In order to ensure the safe operation of emergency flotation system for helicopters and trigger reliably in the process of impacting on water, the reliability of sensor module, the key component of the system, is analyzed. Based on the systematic understanding of k/n(G) voting system composed of different types of units, Monte Carlo simulation platforms of sensor module under different logic relations are built by using Matlab/Simulink, and the corresponding simulation & theoretical calculation are carried out. The results show that it is feasible and effective to apply Monte Carlo method to reliability analysis of sensor module. According to the results of functional hazard analysis and reliability analysis, the 3/5 voting system is more suitable for the sensor module of the helicopter emergency flotation system. This provides a technical route for the logical relationship selection and reliability design of similar modules.