In the opened PPT document, right-click on the blank space of any PPT slide page and select "Format Background"; Or click the design tab and select "Format Background" in the background style on the right.

In the pop-up "Background Format" window, select "Fill" on the left, and you will see four fill modes: solid color fill, gradient fill, picture or texture fill and pattern fill. You can not only insert your favorite picture background, but also set the PPT background to solid color or gradient color.

Click "File" to open the "Insert Picture" dialog box, select the storage path of the picture, and then press "Insert" to insert the prepared PPT background picture;

Then return to the Format Background window. The last step is just to insert a PPT background picture for this slide. If you want to apply the same PPT background picture to all slides, click the "Apply All" button in the lower right corner of the "Format Background" window;

In the version, the "Set Background Format" window has three effects of modifying and beautifying the PPT background picture: picture correction, picture effect and artistic effect. It can adjust the brightness contrast of the picture or change the color saturation and hue, recolor or achieve the effects of line drawing, photocopying and crayon smoothing.