1. Open the WORD document to be operated, with the cursor behind the directory, click "Delimiter" in the page layout tab, and insert a continuous section break.

2. Click Page Number on the Insert tab to insert a page number for the document.

3. Then click Link to Previous Title in the toolbar.

4. Select "Format Page Number" with the right mouse button at the page number.

5. Then enter "1" after the starting page number, and click OK.

6. Stop the cursor at the page number of the table of contents. Similarly, click the right mouse button to open "Format Page Number", and then select the Roman numerals after the number format, set the actual page number to I or I, and click OK.

7. Return to the main document and find that the page number of the directory has been successfully set with Roman numerals.