1. The attribute -webkit-overflow-scrolling: touch must be added to all overflow: scroll elements on the mobile side.
2. Don't leave the document flow when the parent element can't leave the document flow.
3. After the child element iframe is loaded, the overflow: scroll property of the parent element can be overridden asynchronously (this method may be unsuccessful).
4. If the above is not resolved, give the child element a min-height, the size is not limited (slightly larger than the best effect), to help safari build ScrollView (pro-test is the most effective).