Based on a data from 2007 to 2019 rural statistical yearbooks and other sources about fertilizers, livestock excrement, and pesticide pollutions of Hunan Province, and applying the inventory analysis method and the decoupling theory, this study seeks to uncover the spatiotemporal variation patterns of agricultural non-point source pollution in Hunan Province, to examine its intrinsic decoupling relationship with grain production, and to provide a theoretical basis for managing agricultural production. Results reveal that: 1) Throughout the study period, the intensity of agricultural non-point source pollutants in Hunan Province demonstrated a consistent downward trend. Among them, the intensity of livestock pollution emissions decreased by 35.16%, from 60.21 kg/hm2 in 2017 to 38.04 kg/hm2 in 2019; the intensity of fertilizer pollution emissions and pesticide pollution emissions decreased by 6.05% and 10.13%, respectively, indicating that the policy control measures for agricultural non-point source pollution were effective; 2) The emission intensity of pesticide and livestock pollution showed a significant aggregation effect, with high emission areas mainly distributed in central, southern, and eastern Hunan, while the high-value area of fertilizer pollution gradually located in eastern Hunan; And 3) the control of agricultural non-point source pollution in Hunan Province was notably effective, with the coupling and decoupling characteristics between grain production and the emission intensity of the three types of pollutants occurring in distinct phases. Lastly, the paper proposes the following policy recommendations, optimizing the structure of livestock and poultry breeding, regulating the amount of fertilizer application while ensuring grain production, and advocating the reduction of pesticide usage and the implementation of effective pest control technology.