Abstract: The traditional model reference adaptive system lacks the correction mechanism of uncertain factors such as motor current detection errors, system noise, etc., which causes error of rotor position estimation and harmonics of the phase currents. In order to improve accuracy and robustness of rotor position estimation, as well as suppressing the current harmonics, a model reference adaptive system based on dead zone functions was proposed that designed an adaptive law based on dead zone functions. The effectiveness of the method was verified by simulation and experiments. The results verify that the method based on dead zone functions can improve accuracy of rotor position estimation and suppress the harmonic currents effectively. The position estimation error is reduced from 0.062 rad to 0.042 rad. The experimental results show that the rotor position estimation error is reduced by 32% and the 5 th and 7 th harmonic contents are reduced by 39% and 34% respectively.