您有两个不合格的Word对象引用：

You have two unqualified references to Word objects:

objSelection.Style = ActiveDocument.Styles("Heading 1")

出现两次，需要：

objSelection.Style = objWord.ActiveDocument.Styles("Heading 1")

否则，您将创建一个不能销毁的Word的隐式引用你的代码。

Otherwise you're creating an implicit reference to Word that you can't destroy in your code.