Abstract: To eliminate the torque ripple generated in the zero-sequence circuit of an open-winding permanent magnet synchronous motor (OW-PMSM), an opposing torque can be generated by injecting additional current to cancel it out. However, this calculation process requires high accuracy of flux linkage parameters. To more accurately calculate the reference value of the injected current, a torque ripple suppression method was proposed based on an adaptive back electromotive force (EMF) observer (ABEO), obtaining precise information on the back EMF generated by the permanent magnet flux linkage, the zero-sequence back EMF, and the zero-sequence current in the next control cycle. Based on the observed values, the reference value of the injected current was calculated to be capable of eliminating the errors resulted from parameter mismatches and digital delays, achieving better torque ripple suppression. Additionally, a deadbeat predictive current control method with strong parameter robustness was proposed in this paper, constructing an adaptive observer to observe the disturbances caused by parameters mismatch in the current loop, compensating the reference voltage to ensure the performance of the current loop even in mismatched motor parameters. Finally, comparative experiments were carried out to demonstrate the effectiveness and superiority of the proposed method.