Abstract: To improve the encoding efficiency of the current visual secret sharing schemes,a novel encoding algorithm,self-adaptive multi-pixel encoding (SME),was proposed. SME scans a secret image row by row or column by column till meeting a different type pixel or reaching the end,and then fills the encrypted pixels with the length of the scanning span into each share. All the shares have the same dimension as the original image. The analysis and experiment results show that the proposed algorithm is well suitable for all kinds of access structures such as threshold structures and general access structures and can achieve a good quality of decrypted images for all kinds of input images such as black-white,gray-scale and chromatic images,and high encoding efficiency and low complexity are its main advantages.