Abstract: The traditional single-source evaporation model only considers vegetation evaporation but not soil evaporation, and there are limitations in the calculation of regional potential evaporation. This paper introduces a dualsource evaporation model, which can consider both vegetation and soil evaporation. Taking mountain area of western Liaoning Province as an example, the accuracy of the dual-source evaporation calculation model is discussed based on the measured evaporation data. The results show that the dual-source evaporation calculation model has good accuracy in the mountain area of western Liaoning Province, which is significantly better than the traditional single-source evaporation model.