The leaching of soil nitrogen and phosphorus in the citrus orchard of Zigui County of the Three Gorges Reservoir Area were studied in August 2017 by using the original soil column simulated experiment, and the effects of different fertilization treatments on soil nitrogen and phosphorus leaching were discussed, which provided a theoretical basis for the prevention and control of agricultural non-point pollution in this region. The results were as follows: (1) The leaching concentration of total nitrogen (TN), total phosphorus (TP), nitrate nitrogen (NO₃^-—N) and ammonium nitrogen (NH₄⁺—N) in the filtrate of citrus orchard under different fertilization treatments were 37.16~163.07, 0.61~6.69, 27.54~79.38 and 2.37~7.10 mg/L, respectively. (2) Both the amount of fertilizer and the type of fertilization were the factors affecting the leaching of nitrogen and phosphorus in soil. Under the same fertilization treatment, the soil nitrogen and phosphorus leaching concentration increased significantly with the increase of the amount of fertilizer, and then the increase reduced. Under the same nitrogen application rate, the leaching of nitrate nitrogen was most affected by the type of fertilizer, while the leaching of ammonium nitrogen was the smallest. (3) In soil filtrate, nitrate nitrogen was the main leaching form of soluble nitrogen, and the ratio of leaching loss and total nitrogen leaching was 29.72%~46.18%, and the proportion of NH₄⁺—N leaching loss was 1.09%~2.05%. The finding indicate that the treatment of constant compound fertilizer is more beneficial to the conversion of fertilizer nitrogen to soluble nitrogen for plant absorption and to reduction the accumulation of nitrogen in soil after fertilization.