Rotating high frequency signal injection method was well suited for the rotor position detection of interior permanent magnet synchronous motor in the zero and low speed range, for the stability of the injected signals form and the independence from motor parameters. The square wave voltage injection method was used to detect the magnetic pole, and the finite element simulation was performed to select the amplitude and duration of the injected square wave voltage, effectively reducing the detecting time. The effect of filters and signal discretization on the accuracy of position estimation was analyzed. It was proposed that the phasefrequency characteristic curve near the center frequency of the bandpass filter could be fitted to a line segment in the lowspeed range. The relationship between the required compensation angle and the motor rotation speed was deduced. On the basis of the theoretical analysis, experiments were carried out on the prototype platform based on DSP28335. The results showed that the magnetic pole judgment process was stable and took a short time. The compensated position estimation was obviously improved compared with that before compensation. The dynamic performance of the system during the speed regulation process was good.