In order to effectively improve the image encryption effect and security, an improved logistic mapping image encryption algorithm is designed. Firstly, on the basis of cubic mapping and logistic mapping, a new two-dimensional discrete mapping is proposed to overcome the problem of narrow chaotic interval and fewer parameters. The image is scrambled by improved logistic mapping. Then the scrambled image is processed by bitwise exclusive or operation between adjacent pixels, and the final cipher-text image is obtained by crossover operation. The simulation results show that the algorithm is simple and easy to execute, has good security, strong anti-attack ability and high efficiency.