Why does the short-focus lens distort the picture when shooting, and how can we eliminate this distortion?

Short focus is wide angle, and wide angle lens is characterized by large viewing angle, so shooting the same scene can be closer to the subject than medium telephoto lens. But because the perspective effect of close-up shooting is stronger, the picture distortion you said is actually called perspective deformation. In order to reduce the perspective effect of wide-angle lens, it is necessary to keep the subject at a certain distance from the lens and pay attention to the control of the center point. For example, shooting a house with 10 floor, it is best to shoot at a height equivalent to about 5 floors, which can effectively prevent the illusion of falling. But perspective deformation is often used to express tension, such as making industrial films.