diff --git a/src/dfm-search/dfm-search-lib/contentsearch/contentstrategies/indexedstrategy.cpp b/src/dfm-search/dfm-search-lib/contentsearch/contentstrategies/indexedstrategy.cpp
index 2af7bef6..fba8bb1a 100644
--- a/src/dfm-search/dfm-search-lib/contentsearch/contentstrategies/indexedstrategy.cpp
+++ b/src/dfm-search/dfm-search-lib/contentsearch/contentstrategies/indexedstrategy.cpp
@@ -49,7 +49,6 @@ void ContentIndexedStrategy::initializeIndexing()
 
 void ContentIndexedStrategy::search(const SearchQuery &query)
 {
-    m_cancelled.store(false);
     m_results.clear();
 
     try {
@@ -369,7 +368,7 @@ void ContentIndexedStrategy::processSearchResults(const Lucene::IndexSearcherPtr
     m_results.reserve(m_results.size() + static_cast<int>(docsSize));
 
     for (int32_t i = 0; i < docsSize; ++i) {
-        if (m_cancelled.load()) {
+        if (m_cancelledRef && m_cancelledRef->load()) {
             qInfo() << "Content search cancelled";
             break;
         }
@@ -500,9 +499,19 @@ void ContentIndexedStrategy::processSearchResults(const Lucene::IndexSearcherPtr
 
 void ContentIndexedStrategy::performContentSearch(const SearchQuery &query)
 {
+    // 防御性空指针拦截：正常流程 m_cancelledRef 由引擎注入，非空；
+    // 若注入失败（setCancelledFlag 拒绝空指针），此处拦截避免底层
+    // SearchCancellationGuard / CancellableCollector 解引用 nullptr 导致 SIGSEGV。
+    if (!m_cancelledRef) {
+        qWarning("ContentIndexedStrategy::performContentSearch: cancellation flag is null, aborting search");
+        emit errorOccurred(SearchError(ContentSearchErrorCode::ContentIndexException));
+        emit searchFinished(m_results);
+        return;
+    }
+
     // RAII 守护类：自动管理取消标志的生命周期
     // 构造时设置标志，析构时自动清理（即使发生异常）
-    SearchCancellationGuard guard(&m_cancelled);
+    SearchCancellationGuard guard(m_cancelledRef);
 
     try {
         // 获取索引目录
@@ -543,7 +552,7 @@ void ContentIndexedStrategy::performContentSearch(const SearchQuery &query)
         Collection<ScoreDocPtr> scoreDocs;
         try {
             // 创建可取消的收集器
-            boost::shared_ptr<CancellableCollector> collector = newLucene<CancellableCollector>(&m_cancelled, maxResults);
+            boost::shared_ptr<CancellableCollector> collector = newLucene<CancellableCollector>(m_cancelledRef, maxResults);
 
             // 执行搜索，使用自定义收集器
             qInfo() << "Content search execution start:" << query.keyword();
@@ -555,7 +564,7 @@ void ContentIndexedStrategy::performContentSearch(const SearchQuery &query)
                     << "Total hits:" << collector->getTotalHits()
                     << "Collected:" << scoreDocs.size()
                     << "Keyword:" << query.keyword()
-                    << "Cancelled" << m_cancelled.load();
+                    << "Cancelled" << (m_cancelledRef ? m_cancelledRef->load() : false);
         } catch (const SearchCancelledException &e) {
             qInfo() << "Content search cancelled during execution";
             emit searchFinished(m_results);
@@ -588,7 +597,8 @@ void ContentIndexedStrategy::performContentSearch(const SearchQuery &query)
 
 void ContentIndexedStrategy::cancel()
 {
-    m_cancelled.store(true);
+    if (m_cancelledRef)
+        m_cancelledRef->store(true);
 }
 
 DFM_SEARCH_END_NS
diff --git a/src/dfm-search/dfm-search-lib/core/genericsearchengine.cpp b/src/dfm-search/dfm-search-lib/core/genericsearchengine.cpp
index 5d8565c9..46248055 100644
--- a/src/dfm-search/dfm-search-lib/core/genericsearchengine.cpp
+++ b/src/dfm-search/dfm-search-lib/core/genericsearchengine.cpp
@@ -52,8 +52,6 @@ void GenericSearchEngine::init()
     // 连接控制信号（主线程 -> 工作线程）
     connect(this, &GenericSearchEngine::requestSearch,
             m_worker, &SearchWorker::doSearch);
-    connect(this, &GenericSearchEngine::requestCancel,
-            m_worker, &SearchWorker::cancelSearch, Qt::DirectConnection);
 
     // 连接结果信号（工作线程 -> 主线程）
     connect(m_worker, &SearchWorker::resultFound,
@@ -66,6 +64,9 @@ void GenericSearchEngine::init()
     // 设置策略工厂
     setupStrategyFactory();
 
+    // 将引擎级取消标志注入 worker，使策略能即时读取取消状态
+    m_worker->setEngineCancelledFlag(&m_cancelled);
+
     // 启动工作线程
     m_workerThread.start();
 }
@@ -144,11 +145,9 @@ SearchResultExpected GenericSearchEngine::searchSync(const SearchQuery &query)
 
 void GenericSearchEngine::cancel()
 {
+    // 设置取消标志，工作线程通过注入的 flag 即时响应
     m_cancelled.store(true);
 
-    // 发射信号请求工作线程取消搜索
-    emit requestCancel();
-
     // 停止批处理定时器
     m_batchTimer.stop();
 
@@ -218,6 +217,8 @@ void GenericSearchEngine::handleErrorOccurred(const DFMSEARCH::SearchError &erro
 
 SearchResultExpected GenericSearchEngine::doSyncSearch(const SearchQuery &query)
 {
+    // 重置取消标志，避免上次搜索的取消状态残留（与异步 search() 一致）
+    m_cancelled.store(false);
     // 重置同步搜索状态
     m_results.clear();
     m_lastError = SearchError(SearchErrorCode::Success);
@@ -244,7 +245,8 @@ SearchResultExpected GenericSearchEngine::doSyncSearch(const SearchQuery &query)
 
     // 检查是否超时
     if (!timeoutTimer.isActive()) {
-        emit requestCancel();
+        // 超时：设置取消标志通知工作线程停止
+        m_cancelled.store(true);
         return DUnexpected<DFMSEARCH::SearchError> { SearchError(SearchErrorCode::SearchTimeout) };
     }
 
diff --git a/src/dfm-search/dfm-search-lib/core/genericsearchengine.h b/src/dfm-search/dfm-search-lib/core/genericsearchengine.h
index f6280be6..ef00f8e0 100644
--- a/src/dfm-search/dfm-search-lib/core/genericsearchengine.h
+++ b/src/dfm-search/dfm-search-lib/core/genericsearchengine.h
@@ -93,11 +93,6 @@ class GenericSearchEngine : public AbstractSearchEngine
                       const DFMSEARCH::SearchOptions &options,
                       DFMSEARCH::SearchType searchType);
 
-    /**
-     * @brief Internal signal to request worker thread to cancel search
-     */
-    void requestCancel();
-
 protected:
     /**
      * @brief Set up the strategy factory for this search engine
diff --git a/src/dfm-search/dfm-search-lib/core/searchstrategy/basesearchstrategy.h b/src/dfm-search/dfm-search-lib/core/searchstrategy/basesearchstrategy.h
index 27a4ba30..205e36fd 100644
--- a/src/dfm-search/dfm-search-lib/core/searchstrategy/basesearchstrategy.h
+++ b/src/dfm-search/dfm-search-lib/core/searchstrategy/basesearchstrategy.h
@@ -5,6 +5,7 @@
 #define BASESEARCHSTRATEGY_H
 
 #include <QObject>
+#include <atomic>
 #include <dfm-search/searchquery.h>
 #include <dfm-search/searchoptions.h>
 #include <dfm-search/searchresult.h>
@@ -53,6 +54,25 @@ class BaseSearchStrategy : public QObject
      */
     virtual void cancel() = 0;
 
+    /**
+     * @brief 注入引擎级取消标志指针（必须注入，否则取消无效）
+     *
+     * 策略只读取引擎的 atomic flag：主线程调 GenericSearchEngine::cancel()
+     * 设 true，工作线程即时响应。flag 必须非空，由 SearchWorker::doSearch
+     * 创建策略后立即注入。
+     *
+     * 注意：不使用 Q_ASSERT，因为它在 Release 构建中会被移除。
+     * 若传入空指针，保持 m_cancelledRef 为 nullptr 并打印警告。
+     */
+    void setCancelledFlag(std::atomic<bool> *flag)
+    {
+        if (!flag) {
+            qWarning("BaseSearchStrategy::setCancelledFlag: flag is null, cancellation will be ignored");
+            return;
+        }
+        m_cancelledRef = flag;
+    }
+
 Q_SIGNALS:
     /**
      * @brief 找到搜索结果信号
@@ -72,7 +92,7 @@ class BaseSearchStrategy : public QObject
 protected:
     SearchOptions m_options;
     SearchResultList m_results;
-    std::atomic<bool> m_cancelled { false };
+    std::atomic<bool> *m_cancelledRef { nullptr };
 };
 
 DFM_SEARCH_END_NS
diff --git a/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.cpp b/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.cpp
index 3cb1db6c..38940277 100644
--- a/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.cpp
+++ b/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.cpp
@@ -43,6 +43,14 @@ void SearchWorker::doSearch(const SearchQuery &query,
         return;
     }
 
+    // 注入引擎级取消标志，使策略能即时响应取消
+    if (!m_engineCancelled) {
+        qWarning("SearchWorker::doSearch: m_engineCancelled is null, aborting search");
+        emit errorOccurred(SearchError(SearchErrorCode::InternalError));
+        return;
+    }
+    m_strategy->setCancelledFlag(m_engineCancelled);
+
     // 连接信号
     connect(m_strategy.get(), &BaseSearchStrategy::resultFound,
             this, &SearchWorker::resultFound);
@@ -55,11 +63,4 @@ void SearchWorker::doSearch(const SearchQuery &query,
     m_strategy->search(query);
 }
 
-void SearchWorker::cancelSearch()
-{
-    if (m_strategy) {
-        m_strategy->cancel();
-    }
-}
-
 DFM_SEARCH_END_NS
diff --git a/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.h b/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.h
index 57ca4c00..7996281c 100644
--- a/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.h
+++ b/src/dfm-search/dfm-search-lib/core/searchstrategy/searchworker.h
@@ -29,6 +29,8 @@ class SearchWorker : public QObject
 
     void setStrategyFactory(std::unique_ptr<SearchStrategyFactory> factory);
 
+    void setEngineCancelledFlag(std::atomic<bool> *flag) { m_engineCancelled = flag; }
+
 public Q_SLOTS:
     /**
      * @brief 执行搜索操作
@@ -37,11 +39,6 @@ public Q_SLOTS:
                   const DFMSEARCH::SearchOptions &options,
                   DFMSEARCH::SearchType searchType);
 
-    /**
-     * @brief 取消搜索操作
-     */
-    void cancelSearch();
-
 Q_SIGNALS:
     /**
      * @brief 搜索结果信号
@@ -61,6 +58,7 @@ public Q_SLOTS:
 private:
     std::unique_ptr<SearchStrategyFactory> m_strategyFactory;
     std::unique_ptr<BaseSearchStrategy> m_strategy;
+    std::atomic<bool> *m_engineCancelled { nullptr };
 };
 
 /**
diff --git a/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/indexedstrategy.cpp b/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/indexedstrategy.cpp
index d1301f38..0119d216 100644
--- a/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/indexedstrategy.cpp
+++ b/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/indexedstrategy.cpp
@@ -227,7 +227,6 @@ void FileNameIndexedStrategy::initializeIndexing()
 
 void FileNameIndexedStrategy::search(const SearchQuery &query)
 {
-    m_cancelled.store(false);
     m_results.clear();
 
     if (!QFileInfo::exists(m_indexDir)) {
@@ -438,7 +437,7 @@ void FileNameIndexedStrategy::executeIndexQuery(const IndexQuery &query)
     Collection<ScoreDocPtr> scoreDocs;
     try {
         // 创建可取消的收集器
-        boost::shared_ptr<CancellableCollector> collector = newLucene<CancellableCollector>(&m_cancelled, maxResults);
+        boost::shared_ptr<CancellableCollector> collector = newLucene<CancellableCollector>(m_cancelledRef, maxResults);
 
         // 执行搜索，使用自定义收集器
         searcher->search(luceneQuery, collector);
@@ -462,7 +461,7 @@ void FileNameIndexedStrategy::executeIndexQuery(const IndexQuery &query)
 
     // 实时处理搜索结果
     for (int i = 0; i < docsSize; i++) {
-        if (m_cancelled.load()) {
+        if (m_cancelledRef && m_cancelledRef->load()) {
             qInfo() << "Filename search cancelled";
             break;
         }
@@ -796,7 +795,8 @@ BooleanQueryPtr FileNameIndexedStrategy::buildBooleanTermsQuery(const IndexQuery
 
 void FileNameIndexedStrategy::cancel()
 {
-    m_cancelled.store(true);
+    if (m_cancelledRef)
+        m_cancelledRef->store(true);
 }
 
 DFM_SEARCH_END_NS
diff --git a/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/realtimestrategy.cpp b/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/realtimestrategy.cpp
index cfa6ef81..6f209118 100644
--- a/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/realtimestrategy.cpp
+++ b/src/dfm-search/dfm-search-lib/filenamesearch/filenamestrategies/realtimestrategy.cpp
@@ -25,7 +25,6 @@ FileNameRealTimeStrategy::~FileNameRealTimeStrategy() = default;
 
 void FileNameRealTimeStrategy::search(const SearchQuery &query)
 {
-    m_cancelled.store(false);
     m_results.clear();
 
     // 从搜索选项获取参数
@@ -66,7 +65,7 @@ void FileNameRealTimeStrategy::search(const SearchQuery &query)
     int count = 0;
     QSet<QString> visitedDirs;   // 防止符号链接循环
 
-    while (!directoryStack.isEmpty() && count < maxResults && !m_cancelled.load()) {
+    while (!directoryStack.isEmpty() && count < maxResults && !(m_cancelledRef && m_cancelledRef->load())) {
         // 取出一个目录进行处理
         QString currentDir = directoryStack.pop();
 
@@ -103,7 +102,7 @@ void FileNameRealTimeStrategy::search(const SearchQuery &query)
 
         // 处理当前目录中的每个条目
         for (const QFileInfo &info : std::as_const(entries)) {
-            if (m_cancelled.load() || count >= maxResults) {
+            if ((m_cancelledRef && m_cancelledRef->load()) || count >= maxResults) {
                 break;
             }
 
@@ -314,7 +313,8 @@ bool FileNameRealTimeStrategy::matchWildcard(const QString &fileName, const QStr
 
 void FileNameRealTimeStrategy::cancel()
 {
-    m_cancelled.store(true);
+    if (m_cancelledRef)
+        m_cancelledRef->store(true);
 }
 
 DFM_SEARCH_END_NS
diff --git a/src/dfm-search/dfm-search-lib/ocrtextsearch/ocrtextstrategies/indexedstrategy.cpp b/src/dfm-search/dfm-search-lib/ocrtextsearch/ocrtextstrategies/indexedstrategy.cpp
index b2becabd..3f2ab427 100644
--- a/src/dfm-search/dfm-search-lib/ocrtextsearch/ocrtextstrategies/indexedstrategy.cpp
+++ b/src/dfm-search/dfm-search-lib/ocrtextsearch/ocrtextstrategies/indexedstrategy.cpp
@@ -48,7 +48,6 @@ void OcrTextIndexedStrategy::initializeIndexing()
 
 void OcrTextIndexedStrategy::search(const SearchQuery &query)
 {
-    m_cancelled.store(false);
     m_results.clear();
 
     try {
@@ -366,7 +365,7 @@ void OcrTextIndexedStrategy::processSearchResults(const Lucene::IndexSearcherPtr
     m_results.reserve(m_results.size() + static_cast<int>(docsSize));
 
     for (int32_t i = 0; i < docsSize; ++i) {
-        if (m_cancelled.load()) {
+        if (m_cancelledRef && m_cancelledRef->load()) {
             qInfo() << "OCR text search cancelled";
             break;
         }
@@ -510,8 +509,18 @@ void OcrTextIndexedStrategy::processSearchResults(const Lucene::IndexSearcherPtr
 
 void OcrTextIndexedStrategy::performOcrTextSearch(const SearchQuery &query)
 {
+    // 防御性空指针拦截：正常流程 m_cancelledRef 由引擎注入，非空；
+    // 若注入失败（setCancelledFlag 拒绝空指针），此处拦截避免底层
+    // SearchCancellationGuard / CancellableCollector 解引用 nullptr 导致 SIGSEGV。
+    if (!m_cancelledRef) {
+        qWarning("OcrTextIndexedStrategy::performOcrTextSearch: cancellation flag is null, aborting search");
+        emit errorOccurred(SearchError(OcrTextSearchErrorCode::OcrTextIndexException));
+        emit searchFinished(m_results);
+        return;
+    }
+
     // RAII guard: automatically manage cancellation flag lifecycle
-    SearchCancellationGuard guard(&m_cancelled);
+    SearchCancellationGuard guard(m_cancelledRef);
 
     try {
         // Get index directory
@@ -551,7 +560,7 @@ void OcrTextIndexedStrategy::performOcrTextSearch(const SearchQuery &query)
         Collection<ScoreDocPtr> scoreDocs;
         try {
             // Create cancellable collector
-            boost::shared_ptr<CancellableCollector> collector = newLucene<CancellableCollector>(&m_cancelled, maxResults);
+            boost::shared_ptr<CancellableCollector> collector = newLucene<CancellableCollector>(m_cancelledRef, maxResults);
 
             // Execute search with custom collector
             qInfo() << "OCR text search execution start:" << query.keyword();
@@ -563,7 +572,7 @@ void OcrTextIndexedStrategy::performOcrTextSearch(const SearchQuery &query)
                     << "Total hits:" << collector->getTotalHits()
                     << "Collected:" << scoreDocs.size()
                     << "Keyword:" << query.keyword()
-                    << "Cancelled" << m_cancelled.load();
+                    << "Cancelled" << (m_cancelledRef ? m_cancelledRef->load() : false);
         } catch (const SearchCancelledException &e) {
             qInfo() << "OCR text search cancelled during execution";
             emit searchFinished(m_results);
@@ -595,7 +604,8 @@ void OcrTextIndexedStrategy::performOcrTextSearch(const SearchQuery &query)
 
 void OcrTextIndexedStrategy::cancel()
 {
-    m_cancelled.store(true);
+    if (m_cancelledRef)
+        m_cancelledRef->store(true);
 }
 
 DFM_SEARCH_END_NS
diff --git a/src/dfm-search/dfm-search-lib/recentsearch/recentstrategies/recentsearchstrategy.cpp b/src/dfm-search/dfm-search-lib/recentsearch/recentstrategies/recentsearchstrategy.cpp
index 3379cae8..8aa452bc 100644
--- a/src/dfm-search/dfm-search-lib/recentsearch/recentstrategies/recentsearchstrategy.cpp
+++ b/src/dfm-search/dfm-search-lib/recentsearch/recentstrategies/recentsearchstrategy.cpp
@@ -194,7 +194,6 @@ SearchResult RecentSearchStrategy::toSearchResult(const RecentItem &item) const
 
 void RecentSearchStrategy::search(const SearchQuery &query)
 {
-    m_cancelled.store(false);
     m_results.clear();
 
     QElapsedTimer timer;
@@ -203,7 +202,7 @@ void RecentSearchStrategy::search(const SearchQuery &query)
     // Step 1: 从 DBus 拉取全部最近使用记录
     QList<RecentItem> items = fetchRecentItems();
 
-    if (m_cancelled.load()) {
+    if (m_cancelledRef && m_cancelledRef->load()) {
         emit searchFinished(m_results);
         return;
     }
@@ -237,7 +236,7 @@ void RecentSearchStrategy::search(const SearchQuery &query)
 
     int count = 0;
     for (const RecentItem &item : std::as_const(items)) {
-        if (m_cancelled.load() || count >= maxResults) {
+        if ((m_cancelledRef && m_cancelledRef->load()) || count >= maxResults) {
             break;
         }
 
@@ -255,7 +254,8 @@ void RecentSearchStrategy::search(const SearchQuery &query)
 
 void RecentSearchStrategy::cancel()
 {
-    m_cancelled.store(true);
+    if (m_cancelledRef)
+        m_cancelledRef->store(true);
 }
 
 DFM_SEARCH_END_NS