With the continuous growth of population and the change of land use behavior, the ecological environment is constantly disturbed and destroyed, and the bearing capacity of the ecosystem is gradually weakened. As mountain area is one of the most vulnerable geographical types of ecosystem, it is very urgent to study the ecosystem value response caused by land use change. Based on the remote sensing satellite image interpretation, this study obtains the land use classification data of mountainous counties. Using the methods of ecosystem factor weight assignment and spatial autocorrelation analysis, the spatial and temporal evolution of ecosystem service value and its spatial autocorrelation characteristics in Songxian County of western Henan Province from 1990 to 2019 are discussed. The results show that: (1) Songxian County has the highest change range of grassland area, the highest increase of cultivated land area, the highest change rate of unused land, and the obvious increase of construction land and water area. (2) The value of ecosystem services as a whole shows a trend of rapid increase and slow decrease. Among them, the change process of forestland, water area and County Ecosystem Service Value (ESV) is similar as a whole, showing a small growth trend from 1990 to 2000, and then continuing to decline slowly. The functions of hydrological regulation, climate regulation, soil conservation, gas regulation, environmental purification and biodiversity maintenance account for more than 87% of the total value of ESV, which play a decisive role in the land ecosystem of Songxian County. (3) ESV shows the following characteristics as a whole: Luhun reservoir and Yihe River Basin are high ecosystem service value areas, and the ESV value of the southern area is slightly higher than that of the northern area, and the regional differences are significant. In the county, ESV has a strong autocorrelation in spatial distribution, and the trend of continuous enhancement appears after 2010. With the expansion of urban construction land and the continuous reclamation of farmland, ESV loss areas began to spread in towns, mainly due to the urban and rural planning policies and industrial positioning of Songxian County.