Investigating the interplay between ecosystem services and human well-being is crucial for enhancing ecological conservation and achieving a superior quality of development. This research examined the spatial–temporal disparities in ecosystem services and human well-being across 87 counties in Gansu Province using the coupling coordination degree model and geographically weighted regression analysis. The key findings include the following: (1) Over two decades, from 2000 to 2020, ecosystem services in Gansu Province witnessed a financial appreciation of approximately CNY 29.32 billion. The distribution displayed a notable trend, with higher values in the southeastern counties, particularly in Gannan and Longnan, whereas lower values prevailed in the Hexi area. (2) The well-being of the populace experienced a substantial enhancement, registering a 75% increase during the same period, characterized by higher well-being indices in the north, especially in Hexi, and the lowest indices in Gannan and the Linxia sector of Longzhong. (3) The coupling coordination degree between ecosystem services and human well-being escalated from 0.412 to 0.587, transitioning from moderate dysfunction to moderate coordination over the two decades. Regions such as Hexi and Gannan recorded a moderate discordance in their coupling coordination, whereas regions including Longzhong, Longnan, and Longdong demonstrated a more stable, basic coordination. (4) Influences on the coupling coordination degree between county ecosystem services and human well-being displayed significant spatial variability, often aligned along distinct geographic bands. Economic and natural foundations were predominantly aligned southeast to northwest, while investment and urbanization levels were more prominent from west to east, and industrialization levels were distributed along an east–west axis.
