Abstract: In order to explore the effects of different opening ways of irrigator of deep pit irrigation on the wetting body, designing three kinds of irrigators which are bottom opening, side opening, the bottom and sides at the same time opening, the indoor mechanism experiments about infiltration characteristics under the sandy loam soil condition were done. The results showed that: the opening ways of irrigator has great impact for the cumulative infiltration, wetting front migration distance of three spatial and soil moisture. The power function was used to fit the relationship between the migration distance for every direction of the wetting front and time. On the basis of analyzing the shape of wetting body for three kinds of irrigators, the wetting body volume calculation model was built, and the accuracy of the model was verified. It is concluded that in the actual application process, the irrigator of side opening is suit for shallow root distribution crops, and the irrigator of bottom opening is suit for deeper root distribution crops.