Given that there is no effective method for sensorless control of permanent magnet synchronous machine (PMSM) in the whole speed range currently, a novel phase-locked loop (PLL) based transition strategy for hybrid sensorless control is proposed in this paper. At standstill and low speed range, rotating high frequency injection method is used. In the other speed range, it is realized by extended Kalman filter observer. With the proposed PLL strategy, the phase angle can approximate with each other and their difference between both methods can be fast compensated. By the finite state machine logic existing 4 states and 2 transit flags based on the PLL, the different sensorless control methods are unified within a control logical frame, and the estimated position is switched smoothly. The proposed method has proved its flexibility and reliability by simulation and experimental results theoretically and practically.