The method comprises the following steps:

1. Open the WORD document to be operated, and click the "References" tab in the toolbar above.

2. Stop the cursor where you need to add a reference mark, find the footnote option, and click "Insert Footnote".

3. You can find that the corresponding serial number is automatically added to the position, and at the same time, the cursor jumps to the end of the page, and relevant references can be entered after the serial number.

4. Return to the main document and find that the marking operation of adding references in word has been completed.