In the paper a Chinese remainder theorem based new bio-cryptography scheme is proposed, which is designed in cascade structure and adopts an error correction technique to improve the performance, to tackle the problems in secret sharing based methods. In key retrieval, it greatly brings down the number of operations, avoids exhaustive calculation of tarsus, reduces the computation and improves the efficiency of the algorithm. Finally the software system based the iris features, verifies the new bio-cryptography scheme with cascade structure, experimental results show that this scheme has better practicability and stability, which can resolve big computation problem in retrieving secret.