diff --git a/ukui-search-app-data-service/signal-transformer.cpp b/ukui-search-app-data-service/signal-transformer.cpp
index 7947912..7068dcf 100644
--- a/ukui-search-app-data-service/signal-transformer.cpp
+++ b/ukui-search-app-data-service/signal-transformer.cpp
@@ -26,15 +26,55 @@ SignalTransformer *SignalTransformer::getTransformer()
     return instance;
 }
 
+void SignalTransformer::transform()
+{
+    switch (m_signalType) {
+    case Delete:
+        if (!m_items2BDelete.isEmpty()) {
+            Q_EMIT this->appDBItemsDelete(m_items2BDelete);
+            m_items2BDelete.clear();
+        }
+        break;
+    case Insert:
+        if (!m_items2BInsert.isEmpty()) {
+            Q_EMIT this->appDBItemsAdd(m_items2BInsert);
+            m_items2BInsert.clear();
+        }
+        break;
+    case UpdateAll:
+        if (!m_items2BUpdateAll.isEmpty()) {
+            Q_EMIT this->appDBItemsUpdateAll(m_items2BUpdateAll);
+            m_items2BUpdateAll.clear();
+        }
+        break;
+    case Update:
+        if (!m_items2BUpdate.isEmpty()) {
+            Q_EMIT this->appDBItemsUpdate(m_items2BUpdate);
+            m_items2BUpdate.clear();
+        }
+        break;
+    default:
+        break;
+    }
+}
+
 void SignalTransformer::handleItemInsert(const QString &desktopFilePath)
 {
     QMutexLocker locker(&s_mutex);
+    if ((m_signalType ^ SignalType::Invalid) && (m_signalType ^ SignalType::Insert)) {
+        transform();
+    }
+    m_signalType = SignalType::Insert;
     m_items2BInsert.append(desktopFilePath);
 }
 
 void SignalTransformer::handleItemUpdate(const ApplicationInfoMap &item)
 {
     QMutexLocker locker(&s_mutex);
+    if ((m_signalType ^ SignalType::Invalid) && (m_signalType ^ SignalType::Update)) {
+        transform();
+    }
+    m_signalType = SignalType::Update;
     for(auto it = item.constBegin(); it != item.constEnd(); it++) {
         ApplicationPropertyMap propertyinfo = it.value();
         for (auto i = propertyinfo.constBegin(); i != propertyinfo.constEnd(); i++) {
@@ -46,12 +86,20 @@ void SignalTransformer::handleItemUpdate(const ApplicationInfoMap &item)
 void SignalTransformer::handleItemUpdateAll(const QString &desktopFilePath)
 {
     QMutexLocker locker(&s_mutex);
+    if ((m_signalType ^ SignalType::Invalid) && (m_signalType ^ SignalType::UpdateAll)) {
+        transform();
+    }
+    m_signalType = SignalType::UpdateAll;
     m_items2BUpdateAll.append(desktopFilePath);
 }
 
 void SignalTransformer::handleItemDelete(const QString &desktopFilePath)
 {
     QMutexLocker locker(&s_mutex);
+    if ((m_signalType ^ SignalType::Invalid) && (m_signalType ^ SignalType::Delete)) {
+        transform();
+    }
+    m_signalType = SignalType::Delete;
     m_items2BDelete.append(desktopFilePath);
 }
 
diff --git a/ukui-search-app-data-service/signal-transformer.h b/ukui-search-app-data-service/signal-transformer.h
index a5a2961..e513a64 100644
--- a/ukui-search-app-data-service/signal-transformer.h
+++ b/ukui-search-app-data-service/signal-transformer.h
@@ -34,10 +34,16 @@ class SignalTransformer : public QObject
     Q_OBJECT
 
 public:
+    enum SignalType{
+        Invalid = -1,
+        Delete = 0,
+        Insert,
+        UpdateAll,
+        Update
+    };
     static SignalTransformer *getTransformer();
 
     static QMutex s_mutex;
-
 public Q_SLOTS:
     void handleItemUpdate(const ApplicationInfoMap &item);
     void handleItemUpdateAll(const QString &desktopFilePath);
@@ -49,11 +55,13 @@ private:
     SignalTransformer(QObject *parent = nullptr);
     SignalTransformer(const SignalTransformer &) = delete;
     SignalTransformer& operator = (const SignalTransformer&) = delete;
+    void transform();
 
     ApplicationInfoMap m_items2BUpdate;
     QStringList m_items2BUpdateAll;
     QStringList m_items2BInsert;
     QStringList m_items2BDelete;
+    SignalType m_signalType = SignalType::Invalid;
 
 Q_SIGNALS:
     void appDBItemsUpdateAll(const QStringList&);