Image measure technology and automatic control theory are combined to design and realize an encryption control system based on image processing. The equipment of video capture and image processing technology are used to replace traditional image encryption methods. The image processing result is used as S-DES image encryption algorithm to control experimental system in real time. The simulated results show that the proposed algorithm is a good spatial design algorithm for chaotic keys, and possesses a large space of keys, fairly well encryption effect and excellent security to statistic analyses and different attacks.