Electrochemical corrosion takes place between the copper tube and aluminum fin of tube-fin heat exchanger easily，forming a high thermal resistance layer of Al2O3.Therefore，the performance of the heat exchanger and the entire air conditioning system will be affected.In this paper，48 h and 96 h salt spray corrosion tests were made on the tube-fin heat exchanger respectively.And the performance of the heat exchanger before and after salt spray corrosion was tested.It was found that the change of air pressure drop was less than 5 Pa.The capacity and overall heat transfer coefficient of the heat exchanger decreased by 12.5% and 16.6% after corrosion respectively.The thermal resistance of the heat exchanger increased by 20% at most.