Ridge tillage is a kind of conservation tillage for water harvesting and drought resistance,which is used widely in the rainfed cropland of the semi-arid sandy areas.Through field test of rape planting,the seasonal dynamic variation of soil moisture and aboveground biomass under flat tillage and ridge tillage with different structures were observed,and the theoretical and real yields of rape were also analyzed.The results indicate that compared with flat tillage,ridge tillage increased soil moisture of the plow layer between 3.5% and 12.2%,decreased its fluctuation in the growing season of rape,altered its distribution in the perpendicular profile,and located wetting front in the plow layer,which were convenient for the rape to absorb soil moisture and were positive to alleviate drought stress on rape growth.During the telophase of rape growing season,accumulated rate of dry matter,aboveground biomass,the number of pods per plant and TKW under ridge tillage were larger than flat tillage.However, the lower plant density under ridge tillage with unreasonable structure may cause the decrease of theoretical and real yields of rape.With 25 cm high,1/24 the ratio between ridge height and furrow width,ridge tillage T4 not only had the ecological function of harvesting water and resisting drought disaster,but also enhanced the growth and yield of the rape more obviously.So it is a kind of more suitable cultivation method for rape plant in the semi-arid area.