Three-phase pulse width modulation (PWM) rectifier is widely used in motor control, wind power generation, flexible HVDC and micro grid due to the controllable power factor, sinusoidal grid side three-phase current waveform, stable DC side voltage and so on.In order to improve the reliability of three-phase PWM rectifier, a PWM fault-tolerant control system based on NCAV fault detection method is proposed in this paper.The control system can implement fault-tolerant control in a short time in the case of an open circuit fault has occurred on a single power switch, reduce the impact to the system caused by the single open circuit fault.This system can effectively improve the three-phase current waveform, reduce the output voltage ripple and enhance the overall system performance and reliability when an open circuit fault has occurred on a single power switch.The usefulness of this paper is verified through simulation results.