To restrict the repeating background image in Excel sheet, you can follow these steps:

1. Open the Excel sheet where you have set the background image.
2. Click on the "Page Layout" tab in the ribbon at the top of the screen.
3. Click on the "Background" button in the "Page Setup" group.
4. In the "Sheet Background" dialog box, click on the "Picture" option.
5. Select the image you want to set as the background and click on the "Insert" button.
6. Once the image is inserted, click on the "Options" button in the "Sheet Background" dialog box.
7. In the "Options" dialog box, you will see two options for "Horizontal" and "Vertical" under the "Settings" section.
8. By default, both options are set to "Tile". To restrict the repeating background image, select the option "Center" for both "Horizontal" and "Vertical".
9. You can also select the option "Scale" instead of "Tile" to adjust the size of the image to fit the sheet.
10. Once you have made the changes, click on the "OK" button to apply the settings.

By following these steps, you can restrict the repeating background image in Excel sheet to one way or several times. This will give your Excel sheet a more professional and polished look.