1. A method for recognizing a moving target, comprising: step A, collecting video images that contain backgrounds and moving targets; step B, modeling a first frame of the video images and obtaining a first background model; step C, calculating and obtaining a first differential image according to a second frame of the video images and the first background model; step D, modeling the second frame of the video images and obtaining a second background model; step E, calculating and obtaining a second differential image according to a third frame of the video images and the second background model; step F, calculating and obtaining a first binary image and a second binary image respectively according to the first differential image and the second differential image; step G, obtaining a variation region of the moving target according to the first binary image and the second binary image; and step H, sequentially and repeatedly performing the steps A-G and detecting variation regions of all moving targets.