Air system of fuel cell

The invention discloses an air system of a fuel cell, which comprises a fuel cell stack, a compression device for generating compressed air and conveying the compressed air to the fuel cell stack, a cooling device for cooling the compressed air, and a heat exchanger, and is characterized in that a first air inlet of the heat exchanger is communicated with an air outlet of the compression device, afirst air outlet of the heat exchanger is communicated with an air inlet of the cooling device, an air outlet of the cooling device is communicated with an air inlet of the fuel cell stack, and an air outlet of the fuel cell stack is communicated with a second air inlet of the heat exchanger. The gas with a relatively low temperature exhausted by the fuel cell stack is utilized, the compressed air with a high temperature generated by the compression device and the gas with a low temperature exhausted by the fuel cell stack are subjected to heat exchange in the heat exchanger, so that the temperature of the compressed