In order to suppress the torque ripple of permanent magnet synchronous motor(PMSM),an adaptive linear neural network(CDI-Adaline)harmonic injection method based on deviation current input is proposed. The method uses the q-axis and d-axis current deviations as the input of neural network,and applies 2 adaptive linear neural network links to fit the voltage harmonic compensation components and injects them into the output of the current loop controller to offset the harmonic components in the q-axis and d-axis voltages,thereby suppressing torque ripples. To verify the effectiveness of this method,simulations and experiments of 3 control methods were conducted and compared. The results show that,compared with the conventional double closed-loop control,this method can reduce torque ripple by about 97%. Furthermore,compared with the conventional neural network harmonic injection method,this method can obtain similar torque ripple suppression effect with simpler control structure,more convenient parameter adjustment and easier engineering implementation,and its algorithm running time is reduced by about 60%.