According to the present commonly used method to extract moving object is susceptible to noise and the change of the light, it is difficult to extract moving target complete the problem, put forward a kind of based on the three frame difference and canny edge detection of moving object extraction algorithm. The algorithm firstly to difference of three consecutive frames, then fill in the area, the result of the difference of motion area, then the current frame for Canny edge detection to get the edge image, both get moving object with accurate edge image, and finally moving object images is obtained by area filling, so as to realize the extraction of moving objects. Experiments show that the proposed algorithm can effectively real-time moving object from image sequence extracted.