The invention relates to a color image encrypting method based on a multi-chaos system, which is technically characterized in that the gray value of each pixel of an Input-image is recorded as a two-dimensional matrix P(x,y), S box transformation is performed to the P(x,y), and a transformation result is transformed into a pile of pixel groups P(h*x+y), i.e. P0, P1, P2, P3, to Pn, and the pixel groups are recorded as a sequence Pi; XOR operation is performed to each value of {XL1'} and {XL2'} and each pixel in Pi, i.e. Pi'=Pi +XL2'+XL1', thereby finishing the encrypting process. The invention has the advantages of large key space, high key sensitivity, good security and strong anti-attack ability. The security of the method can be completely independent of the attribute of an image and is especially suitable for the condition with higher security requirement.