Abstract: The nine-phase permanent magnet synchronous motor(PMSM) has the advantages of strong fault tolerance and multiple control degrees of freedom, and has been widely used in high reliability situations. In order to solve the problem of traditional fault-tolerant strategies requiring fault location and algorithm switching when an open circuit fault occurs in the motor winding, a current adaptive fault-tolerant strategy that does not require fault location and algorithm switching for any phase winding open circuit fault at the three neutral points of a nine-phase PMSM is proposed. The current reference general formulas for each harmonic plane is obtained by separating the fault reference angle of the harmonic plane current. When an open circuit fault occurs, the harmonic plane current reference formula directly acts on the control system to achieve active fault tolerance. Due to the deviation of the fault reference angle under closed-loop conditions, an improved repetitive quasi proportional resonance controller is introduced to accurately track the harmonic current before and after the fault, further suppressing torque ripple and current harmonics under open circuit faults, and ensuring steady-state performance before and after the fault. The experimental results validate the feasibility and effectiveness of the proposed strategy.