[Objective] The spatiotemporal changes and factors influencing soil conservation capacity in Linyi City, Shandong Province, before and after the implementation of the “Mountain-River Project” were investigated, in order to provide scientific support for evaluating the project’s effectiveness and future planning in the region. [Methods] Using the InVEST model, the spatiotemporal characteristics of the soil conservation capacity in Linyi City of the years 2018, 2020, and 2022 was assessed. The response relationship between the soil conservation capacity and influencing factors was analyzed from both temporal and spatial dimensions. [Results] The soil conservation capacity of Linyi City in 2018, 2020, and 2022 was 23.12, 29.62, and 53.70 t/(hm²·a), respectively. Spatially, soil conservation capacity showed a pattern of “higher in the northwest-lower in the southeast.” Among the four main influencing factors, precipitation, soil, topography, and vegetation, topography was the primary factor affecting spatial distribution, whereas interannual variation was mainly driven by precipitation. [Conclusion] The soil conservation capacity of Linyi City showed a significant upward trend with distinct spatial and interannual variations. Precipitation plays a more prominent role than ecological engineering in influencing the interannual variation in soil conservation capacity; however, the contribution of ecological engineering has increased.