diff --git a/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBar.java b/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBar.java
index c2cea53a..e5f333c8 100644
--- a/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBar.java
+++ b/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBar.java
@@ -674,7 +674,7 @@ public class QMUITopBar extends QMUIRelativeLayout implements IQMUISkinHandlerVi
      * @param alpha 取值范围：[0, 255]，255表示不透明
      */
     public void setBackgroundAlpha(int alpha) {
-        this.getBackground().setAlpha(alpha);
+        this.getBackground().mutate().setAlpha(alpha);
     }
 
     /**
diff --git a/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBarLayout.java b/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBarLayout.java
index 123eb12e..05ff2beb 100644
--- a/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBarLayout.java
+++ b/qmui/src/main/java/com/qmuiteam/qmui/widget/QMUITopBarLayout.java
@@ -163,7 +163,7 @@ public class QMUITopBarLayout extends QMUIFrameLayout implements IQMUISkinDefaul
      * @param alpha 取值范围：[0, 255]，255表示不透明
      */
     public void setBackgroundAlpha(int alpha) {
-        this.getBackground().setAlpha(alpha);
+        this.getBackground().mutate().setAlpha(alpha);
     }
 
     /**