The reason for this situation is that there is no section break between the table of contents and the text, which can be solved by using the "Page Layout" function and the "Automatically Update Fields" function in word. The specific operation steps are as follows:

1. Position the cursor after the last word in the table of contents, and click the "Page Layout" button in the toolbar, as shown in the following figure;

2. Click the triangle on the right of the separator, and then click Next, as shown in the figure below;

3. Turn to the first page of the text, double-click the number of the page number and change it to "1", and then double-click anywhere in the text, as shown in the figure below;

4. Turn to the directory page, right-click anywhere and click "Update Domain", as shown in the following figure;

5. Select "Update Page Number Only" and click "OK" to complete the setting, as shown in the following figure.