Promoting the construction of ecological civilization is conductive to alleviate the contradiction between ecosystem degradation and the people's high-level requirements for a better life, which leads the regions to achieve a win-win situation between ecological value enhancement and economic growth. This paper quantitatively analyzes the spatial and temporal patterns of ecosystem service values (ESV) in the Pearl River-West River Economic Belt in 2005, 2010, 2015, and 2018 by using the method of the value equivalent factor in unit area, which is modified by biomass and vegetation coverage. Further, this paper constructs a geographically weighted regression (GWR) model based on the STIRPAT model to empirically analyze the spatial heterogeneity and spatial non-stationarity of county economic growth affecting unit area ESV. The results shows that: (1) From the perspective of spatio-temporal variation pattern, the ESV of the study area was 4783.391 billion yuan, 4597.193 billion yuan, 5231.360 billion yuan, and 5074.459 billion yuan in 2005, 2010, 2015, and 2018, respectively, documenting a time-varying trend of decreasing, then increasing, and decreasing again. The contribution of the first classification of land-use types to ESV was ranked as forest land > watershed > grassland > cropland > wetland > desert. From the perspective of spatial trends, the ESV showed an alternative distribution of high and low value areas, and presented a spatial pattern of "low in the west, but high in the east". Some districts and counties located at the border between Guangdong and Guangxi have higher ESV per unit area, which appeared a trend of spreading from east to west. However, ESV in the Pearl River Delta region was hardly affected by the diffusion trend. (2) The number of counties with a significant effect of GDP per capita on ESV per unit area was increasing and concentrated in the eastern, central and northern parts. Among them, the Guangdong section of the Pearl River-West River Economic Belt showed a continuous and significant negative effect. In contrast, the central and northern parts of Guangxi showed a change from negative to positive effect, which is in accordance with the EKC hypothesis. Based on the above results, this paper proposes targeted recommendations. First, further declines in ESV in the Pearl River Delta and its western contiguous parts should be avoided. Second, the central and northern parts of the Pearl River-West River Economic Belt should be given more preferential policies to speed up regional development. Third, the northwestern and southwestern parts should pay more attention to the coordination of economic growth and ecological environment. The results of this paper have important implications to the localized development that balances economic growth and ecological environment.