System for improving recovery efficiency of fuel cell system and control method thereof

The invention relates to a system for improving the recovery efficiency of a fuel cell system, which is characterized in that air supply of an air compressor is connected with a heat stroke inlet of an air-to-air heat exchanger, a heat stroke outlet passes through an intercooler and then is connected with a cathode inlet of a stack, and air outlet of a cathode outlet of the stack is connected with another heat stroke inlet of the air-to-air heat exchanger through a gas-liquid separator; the other heat stroke outlet is connected with a turbine through air supply of an icebreaking auxiliary heater, the turbine drives a compressor motor, the compressor motor drives an air compressor, and the turbine is externally connected with a tail discharge pipe. The structure is simple and compact, components can be effectively integrated, the use safety and reliability are improved, the service life is prolonged, the capacity recovery efficiency is improved, the fuel cell or overall use heat burden is reduced, and the ener