Abstract: In order to solve the problem of collision between multi-tag in radio frequency identification (RFID) system.This paper proposes RFID anti-collision algorithm based on chaotic sequence slotted ALOHA by analyzing slotted ALOHA algorithm.Address code of labels obtain spread-spectrum signal by chebyshev spread-spectrum code.Reader get address code of labels by receiving spread-spectrum signal.An evaluative model for system efficiency is built, and experimental results show that the algorithm can significantly improve system throughput and when offered load is close to N, the throughput is close to the maximum.