Abstract: Agricultural productive services serve as the core engine driving agricultural green transformation, playing a pivotal role in optimizing factor allocation and promoting sustainable production practices. While existing literature has extensively explored the relationship between agricultural productive services and pesticide input, empirical research on the underlying opportunistic behavior mechanisms remains scarce. Leveraging microdata from the 2020 China Rural Revitalization Survey (CRRS), this study systematically examines the driving effects of agricultural productive services on pesticide reduction and the regulatory mechanism of opportunistic behavior within this context. The study found that agricultural productive services significantly promoted the reduction of pesticide application. This conclusion was supported by the instrumental variable method and a series of robustness tests. The opportunistic behavior derived from the service market will also weaken the reduction effect of pesticide application services, and improving the level of rural digitalization will help curb agricultural service opportunistic behavior. Heterogeneity analysis further revealed that the pesticide reduction effect of agricultural productive services in the central region was significantly stronger than that in the eastern and western regions; and the pesticide reduction effect of large−scale farmers purchasing agricultural productive services was significantly better than that of small farmers. Further analysis shows that compared with the pesticide application stage, the full−trustee service model has a more significant effect on promoting pesticide reduction. The intrinsic advantage lies in that the full−trustee model effectively constrains opportunistic behavior of service organizations by establishing long−term cooperation−based "relational contracts," thereby promoting scientific pesticide reduction. This study contends that advancing the agricultural productive services market must prioritize governing opportunistic behavior in pesticide application services and curb such behavior through enhanced rural digitalization, ultimately fostering green and high−quality agricultural development. Regions with mature agricultural socialized service markets and moderate−scale farmland transfer should prioritize developing full−trustee agricultural production service models.