Heat source power,wire feeding speed and cooling rate are the key parameters that affect the repair quality of ultrathin compressor blades surfacing.The mathematical model was established,and the numerical solution of surfacing height under different wire feeding speed was calculated.According to the thermal properties of the alloy and the results of the previous titanium alloy test,the heat input range of Inconel718 alloy was derived.According to the repair characteristics of ultra-thin blades,the wire feeding speed 2.54 mm/s was selected to build the heat transfer model.The maximum temperature distribution curve of the weld cross section under different heat input was solved,and the corresponding heat input values were obtained by analysis.On this basis,combined with the theory of fluid heat transfer,the change of fluid temperature and fixture isotherm under different cooling flow rates were solved,and the change curves of the maximum temperature of molten pool and weld section with time were obtained.The results show that when the heat input is 431 W,the wire feeding speed is 2.54 mm/s and the fluid flow rate is 4.6 L/min,better thermal cycling effect can be achieved in the weld zone.The research methods and results provide a reference for the design of surfacing repair process of compressor blades,which has a good engineering application value.