Air system and control method thereof, fuel cell engine and vehicle

The invention discloses an air system and a control method thereof, a fuel cell engine and a vehicle, and relates to the technical field of fuel cell engines. The air system is connected with a fuel cell stack through an air inlet pipeline and an air outlet pipeline, and comprises: a flow adjusting device, which includes an air compressor and an air flow meter that are both arranged on the air inlet pipeline, wherein the air flow meter is arranged at the upstream of the air compressor and used for adjusting the air inlet flow of air to a preset flow value; a temperature adjusting device, whichis arranged on the air inlet pipeline, is positioned at the downstream of the air compressor and is used for adjusting the temperature of the air to a preset temperature value; a pressure adjusting device, which is connected with the air inlet pipeline and used for adjusting the pressure of the air to a preset pressure value; and a humidity adjusting device, which is connected with the air inletpipeline and used for adju