diff --git a/dde-dock/Widgets/windowpreview.cpp b/dde-dock/Widgets/windowpreview.cpp
index e50c23c01..748c466f3 100644
--- a/dde-dock/Widgets/windowpreview.cpp
+++ b/dde-dock/Widgets/windowpreview.cpp
@@ -72,10 +72,11 @@ void WindowPreview::updateCache()
                     cache.setPixel(x, y, pixel);
                 }
             }
+            
+            XDestroyImage(image);
 
-            cache = cache.scaledToWidth(width(), Qt::SmoothTransformation);
-
-            m_cache = new QImage(cache);
+            QImage cacheScaled = cache.scaledToWidth(width(), Qt::SmoothTransformation);
+            m_cache = new QImage(cacheScaled);
         }
     }
 }