You can do this: for example, Notepad: there is a file menu on the main form and a file menu on the sub-form: just change the MergeType property of the two forms to MergerItems in the property window. But if you have other menus, you need to integrate them. For example, if you still have an edit menu to merge (both the main form and the sub-form have edit menus), you can do this: in the property window, change the MergeOrder property of both forms to 1 (the default value is 0, and if you don't change it, your previous file menu will be replaced. It is also possible to change it to other constants, but it should be noted that the values of the two forms must be the same. ), MergeType has also been changed to MergerItems；;