As a key component of the air subsystem of proton exchange membrane fuel cell engines, the humidifier plays a role in humidifying the gas at the cathode inlet of fuel cell stack, and its performance directly determines the performance of battery system. Through the design of humidifier parameter sensitivity experiment, the influences of the inlet flow, pressure, temperature of dry and wet sides and humidity at wet side inlet on the performance of humidifier were explored. The evaluation was conducted based on the performance parameters such as the relative humidity at dry side outlet, dew point approach temperature, water vapour transfer rate and water recovery ratio. The results show that the increase in inlet flow rate of both sides will increase water vapour transfer rate, the humidity at the dry side outlet will decrease, the dew point approach temperature will increase, and the water recovery ratio will decrease. The increase in inlet pressure of both sides will reduce the water vapour transfer rate, the humidity at dry side outlet will increase, the dew point approach temperature will decrease, and the water recovery ratio will increase. The increase in inlet temperature of both sides will increase the water vapour transfer rate, the humidity at dry side outlet will remain stable, the dew point approach temperature will increase, and the water recovery ratio will decrease. The increase in humidity at wet side inlet will increase the water vapour transfer rate, the humidity at dry side outlet will increase, the dew point approach temperature and the water recovery ratio will remain stable.