A scientific understanding of the trade-offs and synergies of ecosystem services is the prerequisite for maintaining the structure, function and health of forest ecosystems, which is conducive to promoting the “win-win” goal of economic development and ecological protection. As an important ecological function area in China, the Qinba Mountain region is responsible for important ecological services such as biodiversity conservation and water conservation, and exploring the trade-offs and synergistic relationships of ecosystem services is important for ecological conservation and high-quality development in this region. This paper analyzes the spatial and temporal characteristics of water conservation, soil conservation, carbon sequestration, and habitat quality services and their synergistic/balancing relationships in the Qinba Mountain region from 1990 to 2020 using tools such as the InVEST model, ArcGIS, and Matlab. The results showed that (1) the overall trend of water connotation, soil conservation and carbon sequestration in the Qinba Mountains is increasing, while the trend of habitat quality is fluctuating and decreasing. The spatial distribution pattern of water conservation and soil conservation services was “high in the southwest and low in the northeast”, while the spatial pattern of habitat quality services was the opposite; the spatial distribution pattern of carbon sequestration services was “low in the middle and high around”. (2) Habitat quality in the Qinba Mountains has a trade-off relationship with water connotation and soil conservation, as water connotation–soil conservation is a synergistic relationship, while carbon sequestration is unrelated to water connotation–soil conservation and habitat quality. (3) The area of habitat quality–water conservation showed a decreasing trend; the area of habitat quality–soil conservation showed an increasing trend; the area of habitat quality-water conservation showed a decreasing trend; the area of habitat quality-soil conservation showed an increasing trend; the area of water conservation-soil conservation service synergistic relationship showed a decreasing and then increasing trend; while the area of carbon sequestration service and In most of the regions, carbon sequestration, soil conservation and habitat quality services are not related to each other.