In the face of potential environmental problems caused by large-scale fertilization of apple orchards, a typical watershed in the gully region area of the Loess Plateau was used as the research area, apple orchards of different tree ages and geomorphic types were selected, and soil moisture changes and the distribution characteristics of nitrogen in the soil profile of orchards of different tree ages were analyzed, which provide a theoretical basis for scientific fertilization and the promotion of sustainable agricultural development. In the Wangdonggou watershed of Changwu County, Shaanxi, apple orchards with different planting years (14, 18, 23, 28, and 32) and geomorphic types (table, ridge, and slope) were selected, 4 cm diameter sampler were used to collect 0—400 cm soil samples from 15 orchard plots at a distance of 1m from each fruit tree, and 12 orchard plots with typical deep section soil samples of 0—600 cm soil were used determine soil moisture, nitrate and ammonium nitrogen content. The results showed that with the increase of orchard planting years, the soil water content and water storage capacity of 0—600 cm decreased significantly, especially at 300—600 cm.The water storage capacity of 14, 23, and 32-year-old orchards was significantly different (P<0.05), and the water storage performance was 14-year-old orchard>23-year-old orchard>32-year-old orchard. The content of ammonium nitrogen in soil mineral nitrogen was low, and basically had no effect on the distribution characteristics of mineral nitrogen. Nitrate nitrogen accounted for a high proportion of mineral nitrogen, and directly affected the distribution of mineral nitrogen in the soil. The nitrate nitrogen content of 0—600 cm among different ages of orchard varied greatly, and the accumulation of nitrate nitrogen in deep soil was common. The nitrate nitrogen accumulation in 18, 23, and 32-year-old sloping orchards 0—200 cm soil accounted for 50%, 41%, and 38% of the 0—400 cm total accumulation amount, showing that the accumulation of soil nitrate nitrogen gradually deepened with the growth of the orchard tree age. The accumulation of nitrate nitrogen in soil increased with the age of the orchard trees. The accumulation of nitrate nitrogen in soil was 32 years old>23 years old>18 years old in the slope land orchards, 28 years old>23 years old in ridge land orchards, and 23 years old>18 years old>14 years old in table orchards. The deep desiccation of orchard soil and accumulation of nitrate nitrogen in the gully area of the Loess Plateau were obvious, and became more serious with the increase of the orchard age.