The agricultural water-saving is the only way to relize the sustainable use of water resources in Xinjiang. Through application of technology under plastic film in cotton production, the paper discussed the features and advantages of the subirrigation technology in Jingou River irrigation district, and further carried out planting cost analysis and benefit analysis of subirrigation under plastic film .The result indicated that subirrigation under plastic film can increase 6 079.5，4 964.5，8 330.4 RMB yuan per hm2 of cotton income respectively, compared with the white Long, pressure drip irrigation under plastic film and conventional small furrow irrigation. The payback period of project is 2.1 years. The indicators above have more outstanding advantages compared with conventional irrigation. Therefore, subirrigation can be put into large scale application in arid irrigation area.