The invention discloses a current harmonic compensation method based on a PID self-learning delay compensator. The method is characterized by comprising firstly, through injecting harmonic current, generating a torque component which is equal to amplitude of an orientation torque and opposite to the orientation torque, to realize compensation on torque ripple of the orientation torque; then, through a PID self-learning delay compensator, the moment component generated by the harmonic current and the orientation torque having no time delay error; finally, using a self-learning chain to predict accumulative error of time delay, providing a delay error prediction self-compensation controller. Beneficial effects of the method are that torque ripple caused by the orientation torque of a motor is restrained, a compensator solves the torque ripple caused by a cogging force, and effectively reduces velocity fluctuation of a driving motor of an electric vehicle, so as to restrain vibration and noise and other phenomenon. The method can make the moment component generated by the harmonic current and the orientation torque have no time delay error, and achieves an objective of improving system response output characteristics.