The present invention belongs to the field of radio frequency identification tag collision-proof technology. It is characterized by that the initial communication rate set by card-reader is less than the rate of normal protocol communication made by tag and card-reader, its value is dependent to the time difference from that card-reader sends signal to that the returned signal of tag is received, after the signal sent by card-reader is received by tag whose distance is most near, said tag can most quickly return signal, so that the communication rate can be defined, under said communication rate other tags can not normally work or return signal, therefore the collision between tags can be prevented. Said invention also provides a radio frequency identification tag based on position information. Said tag includes antenna, distance conversion returned signal time delay circuit, second digital circuit and modulation-demodulation circuit.