The air conditioning system provides the internal environment system of the aircraft for the crew, passengers and equipment, and the performance of air conditioning directly affects the passengers comfort and normal running of the equipment. During the high temperature season, the cooling demand for air conditioning is high, and the frequent failure of air conditioning often affects the safe running of aircraft. With the increasing size of the fleet, how to efficiently manage and control the running of the air conditioning system is an important technical issue for the airline company. Taking the Boeing 737-800 as the research object, this paper uses the aircraft maintenance manual (AMM) and the fault isolation manual ( FIM) , introduces the principle of air conditioning cooling, deeply analyzes the typical faults affecting the cooling performance, and provides effective measures. The air conditioning health monitoring scheme and its implementation path were introduced. Through the application practice of the fleet, this scheme can effectively monitor the cooling performance of air conditioner, greatly improve the maintenance efficiency, ensure the flight operation, enhance the independent innovation ability, and win the reputation of the enterprise.