The invention provides an image 
encryption method based on 
chaotic mapping and 
chaotic S-box substitution in the technical field of image 
encryption, and the method comprises the steps: S10, obtaining a 
color image file, carrying out the Hash calculation, obtaining a Hash value, and calculating a 
system parameter based on the Hash value; step S20, generating four initial values of four-dimensional hyper-
chaotic mapping based on the Hash values, and further obtaining four groups of chaotic pseudo-random sequences; s30, extracting a sequence Wz based on the chaotic pseudo-
random sequence and 
system parameters, and generating a chaotic 
S box by using the sequence Wz and the 
S box using the AES 
algorithm; step S40, performing Arnold scrambling on the 
color image file to obtain a scrambled image, and performing 
byte substitution on the scrambled image by using a chaos 
S box to obtain a substituted image; and S50, performing 
image diffusion encryption on the three components of the RGB in the substitution image by using the chaos pseudo-
random sequence and the 
system parameters to obtain three pieces of 
ciphertext data, and obtaining an encrypted 
image based on each piece of 
ciphertext data. The method has the 
advantage that the security of image encryption is greatly improved.