Position sensorless motor drives have attracted increasing attention in academia and industrial applications due to their advantages of low cost, high reliability, simple hardware circuits, and low maintenance requirements. A variety of position sensorless technologies are reviewed for three operating ranges: zero-low speed domains, medium-high speed domains, and full speed domains. Firstly, the advantages and disadvantages of various position sensorless control methods at zero-low and medium-high speeds domains are comparatively analyzed, respectively. Secondly, the current switching control strategy for full-speed domains operation is sorted out and summarized. Finally, the future development trend of position sensorless control technology for permanent magnet synchronous motor is prospected, and the key problems of follow-up research are pointed out.