During the operation of Radio frequency Identification, the most difficult aspect is the problem of signal collision, as such problem result in lower efficiency of the overall system. How to decrease the problem of collision so as to enhance its identification rate is the hot issue of RFID systems. This dissertation gives two ways for efficient solution to the collision during operation of a RFID system. The SQT (Stride Query Tree) and MQSQT (Minimal Query Set QT) algorithms are improved versions of the Query Tree algorithm on which they are based. The SQT algorithm changes the original method of querying tags into the method of striding layers. It shows that the SQT therefore substantially decreased the collision times during querying, in order to decrease over idling during queries of striding layer, we further modified the production method of information by SQT query, and searched out the next query node by bit logic calculation. This enables the whole system to decrease collision and idling problems in a process named MQSQT. We show in the simulation result that both problems of collision and idling were both improved significantly.