The problem of the secure transmission of digital image has paid more and more attention to the network and this paper designs a special image encryption scheme. Image encryption scheme is designed based on the hyper chaos of generalized five-order Henon mapping and five-order cellular neural network (CNN) system. Firstly, the chaotic sequence X, which is regarded as the initial conditions of CNN system, is generated by the five-order generalized Henon mapping. Then another chaotic sequence Y is produced by the CNN system. At last, the cipher image is generated by the transformation of random sequence Y and the original image. Toward the end, the paper makes the simulation experiment and draws a conclusion that the algorithm of image encryption has strong attack resistance, good safety, and suitable to spread in the network through analyzing the statistical characteristics of the image information entropy, correlation and histogram as well as the key space and the sensitivity.