1. First of all, the image format of official seal and excel handwritten signature is PNG format, and the background of this format is transparent. If it is not in PNG format, it can be simply processed in excel.

Click Insert-Picture, insert the picture into excel, select the picture, click Color-Set transparent color, and remove the background of the picture. The same is true for the setting of handwritten signature.

2. Select the official seal, right-click below and click the handwritten signature to put it on the top.