Understanding the trade-offs and synergies among various ecosystem services and the differences in their driving factors, which is the foundation for effective ecosystem management and improved human well-being. Taking the Loess Plateau in Northern Shaanxi Province as the study area. Firstly, the soil conservation, water production services, grain supply and carbon sequestration services were quantitatively assessed in the the study area in 2018. Secondly, based on the Bayesian network ecosystem service model, key nodes affecting ecosystem services were identified by node importance analysis. Finally, joint probability distribution, probabilistic reasoning and scenario simulation were used to explore the synergistic relationship of ecosystem service trade-offs and their driving factors. The results showed that:(1) The spatial heterogeneity of various ecosystem services was strong in the Loess Plateau of Northern Shaanxi Province. In terms of soil conservation, water production and carbon sequestration services, the spatial distribution of these three services was relatively consistent, that was, the high value area was concentrated in the southeast, and the low value area was in the northwest, showing the distribution characteristics of high in the south and low in the north. But for grain supply, it showed a distribution pattern of high in the middle and low in the north and south. (2) There was a synergistic relationship among soil conservation services, water production services and carbon sequestration services. However, soil conservation, water production and carbon sequestration services had trade-offs with grain supply, respectively. Among them, the synergistic relationship between water production service and carbon sequestration service, and the trade-off relationship between water production service and grain supply were relatively strong. (3) Anthropogenic and natural factors such as land use, precipitation and NPP (Net primary production) were the main driving factors affecting the trade-offs and synergies of ecosystem services in the study area. Among them, land use factors mainly affected the synergetic relationship between the ecosystem services, while precipitation and NPP factors not only affected the synergetic relationship but also restricted the trade-offs relationship to a certain extent. Further research showed that, land use, precipitation and NPP drivers produced the same synergy or trade-off in different states. Conversely, the same drivers in different states would lead to differences in the way of synergy or trade-off. This study had important theoretical and practical value for understanding the complex relationships among various ecosystem services and their driving factors, and for proposing countermeasures and measures to improve ecosystem management and human well-being.