Abstract: The definition of ideal access structure of XOR-based visual cryptography is given in this paper. The characteristics of ideal access structure are analyzed, and the construction algorithm of shares under ideal access structure is designed. Based on the above results, a new algorithm is proposed for dividing the general access structure into some ideal access structures, and the secret sharing and recovering algorithms are presented. Compared with the previous schemes, the proposed scheme realizes the perfect recovery of secret image, and the sizes of shares can be decreased efficiently.