The invention discloses a passive electronic tag two-dimensional positioning method based on a radio frequency identification (RFID) technology. The method comprises the following steps of: firstly, arranging an RFID reader and a passive reference tag, and setting the energy stage of the reader and an identification vector of the tag; secondly, detecting the passive reference tag by the RFID reader, and establishing an identification matrix R of the passive reference tag; thirdly, detecting a tag to be positioned by using the RFID reader, and establishing an identification matrix O of the tag to be positioned; and finally, determining the nearest neighbor tag, and taking the coordinate average value of the nearest neighbor tag as the coordinate of the tag to be positioned. According to the passive electronic tag two-dimensional positioning method, a passive electronic tag is used as a reference tag, so that the problems of large volume and limited service life of active tags in the prior art are solved, and the service life of a positioning system is greatly prolonged; and a reader which can adjust an energy layer is used for adjusting the read-write distance by adjusting the energy layer, so that the distance between the passive RFID electronic tag and the reader is judged and read.