Abstract: signal collision is never avoided in RFID system，so effective anti-collision algorithm is very important.So an improved algorithm-the anti-collision algorithm based on bit sorting algorithm is proposed.The sent bits will be obtained in corresponding timeslots of the competitive frame for all transponders when used the algorithm by using bit sorting algorithm.the computer simulation and compare show that the new algorithm is more steady and effective to solve the problem of anti-collision for multitarget recognition in RFID system compared with other existed anti-collision algorithms in the most application.