To solve the security problem of transmission image across public networks,an image encryption algorithm based on TD-ERCS and lifting wavelet transform is proposed.Firstly,the image is decomposed by lifting wavelet transform horizontally and vertically,and subband images are gotten.Then,according to the sort permutation and the binary XOR operation from the TD-ERCS chaotic series,it can achieve the encryptions of the subband images.After the image recipient receives the encryption subband images,it correctly restore the subband images by decryption algorithm and reconstruct the original images at the receiving end.Finally,The algorithm security is carried out with theory analysis and computer simulation．The experiment results show that the encryption algorithm based on TD-ERCS and lifting wavelet transform is valid and has higher security.