Urethral valve is the component for controlling the urethra open and close, some serious problems will come once the urethral valve is in failure. In order to improve the reliability of urethral valve, the reliability of urethral valve was analyzed using fault tree analysis method. The reliability simulation algorithm was proposed based on fault tree analysis of urethral valve and Monte Carlo method, the reliability index of urethral valve was calculated by simulation, and the simulation results were verified by experiment. The results show that the corrosion and aging of driving bag are the weak links of urethral valve, and the reliability reaches 085 when the average life of urethral valve is 50 000 times, and the reliability simulation algorithm is simple and effective. The research findings can provide the basis for the structural optimization design and reliability analysis of urethral valve.