Abstract: Based on the harvested rainwater technology and engineering facilities, adopted the method of limited supplemental irrigation, the effects of different watering volume, different supplemental irrigation quota, and supplemental irrigation at different growth periods on maize seedling emergence and growth, and effect of yield and water use efficiency were studied for characteristics of less precipitation and uneven spatial and temporal distribution in Loess hilly plateau. Tile research revealed that：（1） when the relative water content of 0-10cm soil was below 24% no watering seeding without seedling emergence, when it was more than 24%, the seedling was emerged, but the rate of seedling emergence was very low, only 20%-21%.（2）In different conditions of soil relative water content, watering 100ml,200ml,300ml,the rate of seedling emergence can be over 90%,and with the increasing of watering volume, seedling was more vigorous.（3） Under the rainfall conditions of this year, the most reasonable volume of filling water was 5m3/667m2. （4） In situation of the limited water volume, the effect of increasing yield was more obvious with supplemental water at maize jointing stage than filling stage.