An indirect stator-quantities control scheme of traction motor is proposed for the traction drive system based on three-phase four-switch fault-tolerant inverter. The indirect stator-quantities control algorithm is aodpted to generate the space voltage vectors for fixing switching frequency of the inverter and reducing electromagnetic torque ripple. An improved observer of stator flux containing saturation limiter is employed to restrain integral drift. The SVPWM algorithm of fault-tolerant inverter is given especially for three-phase four-switch space voltage vector. The neutral voltage compensation model of capacitors is established and a compensation scheme based on PID regulator is proposed for unbalanced neutral voltage on DC link of fault-tolerant inverter. MATLAB/Simulink simulation is carried out to verify the validity and effectiveness of the proposed control strategy.