Scientific assessment of land cover, landscape pattern, and thermal environment in different stages of Beijing’s sub-center and surrounding areas’ construction is significant for future development planning and related policy making. Taking the peripheral planning of Beijing’s Sub-center as the baseline and slightly adjusted as the research area, the remote sensing image data of ZY-3 in 2016, 2018, 2020, and 2022 were selected, and Landsat 8 remote sensing image data from June 1 to September 30 in Google Earth Engine(GEE). Through object-oriented classification, land surface temperature inversion, and correlation analysis methods, the blue and green spatial landscape pattern and the cooling effect of the blue and green space in different periods were quantitatively analyzed. The results showed that: (1) From 2016 to 2022, the area proportion of blue space in the study area gradually increased while maintaining stability, while the area proportion of green space first decreased and then increased; (2) From 2016 to 2022, the distribution of various patch types in the UBGS landscape pattern of Beijing’s sub-center and its surrounding areas has become more and more balanced; (3) During 2016 to 2022, the mean land surface temperature (LST) showed a “rising-falling-rising” fluctuation. The LST of blue space was the lowest, followed by green space, which played a cooling role to a certain extent; (4) Improving the degree of aggregation, reducing the degree of fragmentation of human activities, and reducing the degree of spatial fragmentation can improve the cooling effect of UBGS. In general, the construction of Beijing’s sub-center and surrounding area increases the UBGS area, the landscape pattern distribution is more balanced, and the cooling effect of UBGS is more prominent.