Abstract: This paper designs an experiment of catching and controlling the precipitation by means of covered ridge planted flute in semi-arid field as one way of controlling soil-plant-atmospheric continued system,for receiving and storing precipitation fully and decreasing evaportranspiration and flow-out of water-soil-fertilizer causing by flow and proposed hydrologic balance equation of semi-arid field flut.This experiment indicats that the water input is increased,the water output is decreased,the soil moisture is increased and conserved well in the plant flute by using this means.It's not only advantage of anti-drought and rich crop and build up the stable hydro-control semi-arid agriculture,but also advantage of decreasing the flow-out of water-soil-fertilizer.It has obvious economic effect and ecologic effect.