Abstract: Linear permanent magnet vernier（LPMV） motor have a bright future in long stroke applications due to high efficiency, simple mechanism, and low cost. However, the position sensor increases cost significantly. This paper proposed a sensorless control scheme based on a modified back electromotive force（EMF） observer. This observer was designed to detect back-EMF information and eliminate the low-frequency disturbances. Then, the position and speed information can be detected by phase-locked loop. Meanwhile, the I/F startup method was adopted in the start-up phase, which improved the reliability of startup. Simulation and experiment results verify the feasibility of the proposed mover position estimated method.