Due to the rotor salient polarity, the winding inductance of the interior permanent magnet synchronous motor (IPMSM) changes periodically with the rotor pole position. Considering this characteristic, a rotor initial position detection method of IPMSM based on high frequency signal injection is proposed. The high-frequency signals are injected into the stator two-phase windings in order, the line voltages of the high-frequency signals of the stator winding are extracted, and the initial position angle without considering the rotor magnetic polarity is obtained after calculation. The pulse voltage vector is injected to judge the rotor polarity, so as to obtain the accurate initial position angle. Theoretical analysis and experimental results show that the method has a little dependence on the resistance parameters, and is not affected by the nonlinearity of the inverter and the detection accuracy of the current sensor, so it can accurately detect the initial rotor position angle and meet the requirements of smooth start of the IPMSM.