With the rapid development of diversified media and digital information network, the digital image encryption technology is widely used in the fields of secure preservation, communication, copyright protection and secret communication of graphic images. In view of the shortcomings of the existing image encryption algorithm based on hyperchaos, an improved algorithm is proposed, which optimizes the configuration of pixel scrambling, and further confuses the correlation effect between the plaintext image and the encrypted text image through pixel replacement and encrypted text diffusion process, thereby shortening the iteration time of the superchaotic system. The results show that the distribution of pixel values in the histogram after encryption is very uniform; the NPCR value and UACI value between ciphertexts are 99.652 1% and 33.432 1%, respectively, indicating that the algorithm is extremely sensitive to small changes in encryption keys. The introduction of this method in the new hyperchaotic sequence quantization mode can effectively improve the operation efficiency, and the algorithm has good performance in both security and effective application, and can be widely used in image security communication and other fields.