The invention relates to a motor current harmonic suppression device and method based on an improved repetitive controller. Stator harmonic current stored in a motor body coordinate system is switchedto a dq motor synchronization coordinate system through transformation of coordinates, then the improved repetitive controller is embedded in a current loop, and high-order current harmonics in the current loop are suppressed by high gain of the repetitive controller at specific frequency point, so that the stator harmonic current in the motor body coordinate system is suppressed. The device caneffectively suppress a series of 6k plus/minus 1(k=1, 2,...)-order harmonic components in the stator current, original system parameters need no change for embedding of the improved repetitive controller, and flexibility of an overall control algorithm is improved.