Abstract: By imitating the soil loosening machine, the effects of phosphorus fertilizer deep application on winter wheat root and yield and soil water or available P balance were studied in arid land. The results suggested that phosphorus fertilizer deep application had a significant effect on increasing winter wheat yield by 38.5% than traditional tilling phosphorus fertilizer application, the best treatment was 1/2 P fertilizer at 20 cm and 1/2 P fertilizer at 40 cm, but no significant effect between different application depth(20 cm and 40 cm). It also increased the root weight of winter wheat, especially that of deep root, which had an important role for wheat to absorb water and phosphorus from subsoil. Furthermore, phosphorus fertilizer deep application could improve the efficiency of water application than that of traditional application, respectively increasing 8.4% for three deep application treatments. The direct effect of phosphorus fertilizer deep application was to improve wheat phosphorus nutrition, especially for deep root to absorb phosphorus from subsoil. As a result, the vertical efficiency of phosphorus fertilizer application was higher than that of traditional tilling application, but the risk of phosphorus deficit in subsoil was also higher.