Abstract: As the second largest hydropower project in the world, Baihetan Hydropower Station has attracted much attention for its ecological and environmental effects. It is of great significance to clarify the evolution of ecosystem service value in the reservoir area before and after the construction of Baihetan Hydropower Station for regional ecological restoration and protection. This paper quantitatively analyzes the change of ecosystem service value in Baihetan reservoir area from 2013 to 2022 with the help of equivalent factor method, univariate local Moran's I, etc. based on the relevant data of land use, national agricultural cost and benefit, and geographic information. The results showed that (1) the value of ecosystem services in the reservoir area increased by a total of 2.085 billion yuan in ten years, of which the growth value of regulating services was the largest, about 1.679 billion yuan. (2) The key counties more affected by hydropower development are Ningnan County, Huidong County, Qiaojia County and Dongchuan District, and the key townships are Baihetan Township, Dobuka Township and Luji Township, whose ecosystem service values have been increased to different degrees. (3) The ecosystem service value of the reservoir area generally shows the pattern of “high in the middle and north and low in the south”, with obvious value gain along the Jinsha River. The results show that the development of Baihetan hydropower can promote the ecosystem service function to a certain extent.