[Objective] The spatiotemporal characteristics of agricultural nonpoint source pollution in Shanxi Province during 2011—2022 were analysed and its development trends was predicted in order to provide a scientific reference for the prevention and control of agricultural non-point source pollution in the Shanxi Province. [Methods] The spatiotemporal characteristics of agricultural non-point source pollution in Shanxi Province were analysed using the pollution emission coefficient and equivalent pollution load methods, and an autoregressive integrated moving average (ARIMA) model was established to predict the development trend. [Results] ① In 2022, the agricultural non-point source pollution in Shanxi Province produced 4.74×10⁵ t of COD (chemical oxygen demand), 5 820 t of NH₃-N, 2.86×10⁴ t of total nitrogen (TN), and 4 180 t of total phosphorus (TP). The high-emission areas were located in Lvliang and Yuncheng City, and the low-emission areas were located in Taiyuan and Yangquan City. The equivalent pollution load was 3.95×10¹⁰ m³. The primary pollutant was TN, and the primary source of pollution was animal husbandry. ② From 2011—2022, the developmental trends of the four types of pollutants were consistent. All showed an increase in fluctuation, and the highest value for each pollutant was observed in 2022. The ranking of pollutants in each region was stable, with Yuncheng and Lvliang City always occupying important positions. TN has been the primary pollutant for 12 years, animal husbandry has been the source of the primary pollutant, and the proportion was still rising. ③ By determining model parameters, the ARIMA (1,1,2) model was established for the forecast. During the forecast period, agricultural non-point source pollution in Shanxi Province decreased slightly, and the development trend showed a steady increase. [Conclusion] It is necessary to strengthen the prevention and control of key agricultural pollution accounts and pollutants, reduce the discharge of agricultural nonpoint source pollution, and mitigate its rising trend.