First open MeituXiuXiu and choose to open a picture, and find the picture you want to use as wallpaper on your computer.

After opening the image, find the crop column on the left, find "Free Cut" at the top and pull down. You can see that it can be cut into many sizes.

Find the size behind this column of your desktop. There are various sizes, such as (1600*900?1280*800 1280*1024), etc. according to your computer.

Click OK.

The size has been cut. Here is the before and after comparison. When finished, click Save and Share in the upper right corner, and you can use it as wallpaper.

Generally, after the picture is approved, it is saved in the computer. Return to the desktop and click My Computer to find the approved picture in My Pictures. You can find that the size is now 1600*900.

Finally, right-click the mouse and select Set as Wallpaper. The resolution is not very good.

But the background I like is still very good.