Abstract: Agricultural productive services as soft inputs in the production process offer a new path for realizing large-scale agricultural operations and improving agroecological efficiency by effectively integrating technology, information, and talent into agricultural production. Based on provincial panel data in China from 2005 to 2021, this study constructed a super-efficiency slack-based measure (SBM) model to measure the agroecological efficiency of each province. A kernel density map was created to analyze the temporal evolution trends in agroecological efficiency and to compare its differences across various regions and provinces. A two-way fixed model was used to examine the effects and mechanisms of agricultural productive services on agroecological efficiency. The mediating effect model was used to analyze the mediating role of farmland management scale, agricultural planting structure, and agricultural technology extension. The results showed that from 2005 to 2021, the agroecological efficiency of the entire country and every region showed an upward trend. China’s agroecological efficiency rose from 0.388 in 2005 to 0.893 in 2021. The efficiency consistently ranked as follows: eastern region > western region > central region, and major grain-sales areas > major grain-producing areas ≈ production-sales balance areas. There were significant differences in agroecological efficiency among the provinces (municipalities, autonomous regions). Qinghai, Shanghai, Hainan and Beijing consistently exhibited high agroecological efficiency, while Shanxi, Anhui, Gansu, and Jiangxi had low agroecological efficiency. Agricultural productivity services significantly improved agroecological efficiency, with results remaining valid even after endogeneity and various robustness tests. The estimation results of the intermediary effect showed that agricultural productive services improved agroecological efficiency by expanding the scale of farmland management, adjusting the agricultural planting structure, and promoting agricultural technologies. Compared with the eastern region, agricultural productive services in the western region had an evident effect on agroecological efficiency, whereas agricultural productive services in the central region showed no significant impact on agroecological efficiency. Compared with the major grain-producing areas, agricultural productive services in the production-sales balance areas had a profound effect on the improvement of agricultural ecological efficiency. Therefore, to enhance agroecological efficiency, the agricultural production service system should be further improved by vigorously cultivating and developing specialized and diversified service entities; promoting large-scale management of agricultural land; leveraging the advantages of large-scale service operations provided by agricultural production service organizations; improving the subsidy mechanism for cultivated land protection to prevent the “non-grain” conversion of cultivated land; and improving the technological innovation of agricultural machinery and equipment by accelerating the research, development, and promotion of low-carbon and high-efficiency technologies.