We all might have noticed the creation of a file named "~$filename.docx"(hidden) when opening filename.docx using MS Word
What is the purpose of this file?
Why is it created and what does it contain?
It maintains temporary information about the current state of the document.
Have you ever encountered a crash and when you open Word it asks you to recover certain documents that were being edited? That's where it gets that information.
来源：https://stackoverflow.com/questions/28950333/why-a-file-starting-with-is-created-when-opening-a-word-document