A hybrid chaotic mapping algorithm(HCM) based on 1-DCM (one-dimensional chaotic map) and Lorenz is proposed to address the security issues of low-dimensional chaotic systems and the complexity of high-dimensional chaotic systems. Firstly, the color images are divided into three high 4-bit planes (BP) and low 4-bit planes. By optimizing the parameters and structure of trigonometric function, the new arcsine-sine (AS) function is designedto generate the 1-DCM and permutation matrix, which is constructed to change the plane position and pixel position of the high 12BP to obtain the scrambling plane, which is encrypted by Lorenz chaotic system to produce the selfencryption matrix, with which the low 12BP is encrypted to generate the low bit encryption planes. Then, the ciphertext image is obtained by combining the high bit scrambling plane and low bit encryption plane. The SHA function is also used as the chaotic system's parameter generator, which improves the correlation between plaintext images and the key and resists selective plaintext attacks. The simulation results show that by modularizing the image's high and low bit planes, the encryption process is simplified and improved. The security and reliability of color image transmission are also improved.