Abstract: Aimed at the problems of water and fertilizer leakage that induced by irrigation in vegetable field, root distribution under three irrigation methods and soil water dynamics and leakage from root intensive layers under different irrigation amount water supply were studied by combination of the field experiments and laboratory analysis in tomato field in greenhouse. The results show that the root intensive layer of tomato is the 0–40 cm, the deepest root level is 60 cm. Within the range of 7.5–22.5 mm irrigation water supply, the water distribution decreases progressively along the depth of the soil. Meanwhile, within the range of 7.5–45 mm irrigation water supply, the relationship between irrigation supply and soil water leakage from the intensive root layers has linear correlation. As a result, the indicated parameter is identified in 15.0–22.5 mm for irrigation water leakage control in tomato flowering, fruiting and harvest period. The index can provide reference for integrated management of the root-water-fertilizer system of shallow rooted vegetables.