Understanding the influence mechanism of ecosystem services will provide some useful guides for practical ecological management. However, there is a limited understanding of the driving forces of ecosystem services, especially from the perspective of spatial heterogeneity. This study attempts to fill the gap in current research by examining the driving forces of the spatial heterogeneity of ecosystem services with an integrated spatial approach. The results show that ecosystem services in the Yimeng mountainous area are characterized by obvious spatial heterogeneity with uneven east-west distribution, that land use type is the dominant factor influencing the spatial heterogeneity of ecosystem services and that the combined effect of multiple drivers is more significant than the effect of any single driver in the interaction mechanism. This study will enrich the mechanistic analysis of the spatial heterogeneity of ecosystem services and provide important support for the optimization and sustainable development of ecosystem services in mountainous and hilly complex areas.