Anti-collision is a very common problem in RFID systems，it has a great influence on the whole system efficiency. How to solve this problem effectively is very important for the entire system. For the most commonlyused algorithms based on DFSA，Combines CHI which are both high accuracy and low complexity in estimating thetags to be identified with adaptive frame size and group division，Constructing a method to solve the problem of tagcollision and giving the theoretical derivation. Simulation results show that the error rate of CHI is low，and adaptiveframe size and group division can effectively enhance the system’s throughput and its stability，the method underconstruction improves the efficiency to solve the problem of tag collision.