Maize variety Zhengdan 958 was used as test materialsandthree treatments of bare land planting(B), plastic mulching in spring (SM) and plastic mulching in autumn (AM)were designed to study the effects of plastic mulch on the growth, yield and yield components of spring maize. The results showed that plastic mulch affected the growth and yield of maize. The AM treatment had obvious advantages on increase of plant height, stem diameter, leaf area index, biomass and dry matter accumulation ; The grain yield of AM treatment was 14 280 kg/hm2 and 12 120 kg/hm2 in 2014 and 2015, respectively, which was 14.51% and 18.76% higher than SM treatment and B treatment in 2014 and 10.79% and 76.93% in 2015. The higher yields of AM were due to its higher ears length, ears thick, grain number and grain weight. The AM treatment increased the utilization efficiency of precipitation significantly in two years. In conclusion, plastic mulch application in autumn continuously in the rainfed farmland of semi-arid areaswas optimal measure to increase spring maize yield and water use efficiency.