This study focused on China and based on the land use data in 2000 and 2020, the PLUS model and the GMOP model were comprehensively applied to simulate the land use pattern of the study area in 2040 under three scenarios of natural development, economic development, and ecological protection. Subsequently, the InVEST model was used to quantitatively analyze the changes in habitat quality, water production, carbon storage, and water purification services under different scenarios, and the Comprehensive Ecosystem Service Index (CES) to capture the overall level of ecosystem services. Based on this framework, we systematically analyzed regional differences in ecosystem service responses to land use change across eastern, central, and western China. The results revealed several key findings: (1) The PLUS model delivered high simulation accuracy and proved suitable for projecting land use changes in the study area. Among the three scenarios, land use changes were most pronounced under natural development, followed by economic development. (2) Under the natural development scenario, ecosystem services generally declined across the board. The western region experienced a significant reduction in carbon storage and habitat quality; the central region saw weakened carbon storage and water purification capacities; and the eastern region showed a simultaneous decline across all services. In the economic development scenario, there is a general trend towards degradation of habitat quality and loss of carbon stocks in the three regions. There is a slight increase in water production in the east, but an overall imbalance in ecological functioning. By contrast, the ecological protection scenario led to improvements in carbon storage and habitat quality in the west, ecological stability in the central region, and enhancements in both habitat and carbon storage, along with reduced nitrogen output, in the east. (3) The natural development scenario resulted in the greatest CES losses, with the west suffering the most severe degradation. While the economic development scenario brought some localized improvements, the overall trend of degradation persisted, especially in the eastern urban clusters where ecological functionality declined significantly. Under the ecological protection scenario, the CES in the three regions shows a stabilizing or rebounding trend, and the overall environmental benefits are better than those in the other scenarios, with the most significant improvement in the west. (4) Region-specific drivers of ecosystem service degradation varied: in the west, grassland degradation and the expansion of unused land were the main contributors; in the central region, intensive agricultural expansion played the dominant role; and in the east, continued urban expansion compressed ecological space, leading to service decline. These findings suggest that future land use management in China should adopt region-specific strategies, targeting the dominant drivers in each area with tailored regulatory and ecological restoration approaches. The study offers policy-relevant insights for promoting sustainable development in China and provides a scientific foundation for future land management and optimization efforts.