A novel sensorless control method of surface-mounted permanent magnet synchronous motor (SPMSM) based on high frequency (HF) current signal injection is proposed in this paper. A HF sinusoidal current signal is superimposed into the estimated d-axis, and the rotor position can be demodulated after q-axis voltage is regulated, which is relative to error angle. Ultimately sensorless control can be achieved. Theoretical analysis and simulation validation are carried out. The simulation results indicate that the rotor position and speed can be obtained exactly at low and zero speed. The approach ensures good dynamic and static performances, and can realize accurate position servo control.