Abstract: Ecosystem services are the natural environmental conditions and functions provided by ecosystems and their ecological processes. Quantitative evaluation of ecosystem services is an important prerequisite for sustainability of ecological resources. We analyzed the spatial heterogeneity of ecosystem services and its influencing factors in forest types (conifers, broadleaves and mixed forest) in Beijing using geodetector. Consequently, (1) net primary production (NPP) of coniferous forest (324.08 g·m⁻²·a⁻¹) was greater than that of broad-leaved forest (303.33 g·m⁻²·a⁻¹) and mixed forest (291.74 g·m⁻²·a⁻¹). Environmental improvement services were largest for coniferous forest (251.91 kg·a⁻¹), then mixed forest (215.39 kg·a⁻¹) and broadleaf forest (155.36 kg·a⁻¹), while both production service and soil and water conservation service were largest for broadleaf forest. (2) The main drivers of spatial heterogeneity of ecosystem services in different forest types were meteorological factors. The main drivers of water production and environmental improvement were precipitation and temperature. The main drivers of NPP are temperature, precipitation and radiation. (3) There is a synergistic relationship between water production service, NPP and soil and water conservation, that is, the larger the water production service, the larger the value of NPP and soil and water conservation.(4) The interaction detection showed that most factors, such as elevation and climate factors, interact with each other to explain the spatial heterogeneity of various ecosystem services was strengthened. Therefore, when afforestation is carried out for the purpose of a certain ecological service, the care measures such as irrigation, moisture preservation and heat preservation should be paid attention to, and the influence of topographic factors should be considered comprehensively. The interaction of different impact factors should be fully considered when analyzing the ecosystem service function of plantation.