Plastic film mulching has been shown to increase crop yields in many crop species, but little has been reported how this technology can be applied to winter wheat in rainfed areas. This study determined the effects of different plastic mulching modes on water use and grain yield of winter wheat in a semiarid rain-fed region of Loess Plateau, Northwest China during 2008-2009 and 2009-2010 growing seasons. The experiment was carried out in a randomized complete block design with three replicates, including four treatments: (i) whole field plastic mulching with soil covering on the top of the plastic mulch and bunch-seeding, (ii) whole field plastic mulching without soil cover on the top of the plastic mulch and bunch-seeding, (iii) ridges mulched with plastic film and row-seeding in the furrow, and (iv) un-mulched with row-seeding as control (CK). Results showed that compared to the CK, the mean plastic film mulching increased the grain yield of winter wheat by 49.4% in the 2008-2009 season and 53.2% in the 2009-2010 season, and water use efficiency (WUE) was increased by 11.8% and 14.3% in the two seasons, respectively. The increased grain yield with plastic film mulching was largely attributable to improved plant growth and high water consumption. The grain yield of winter wheat was significantly and positively correlated (r=0.952^*-0.958^*) with water consumption during the growth period. Winter wheat with plastic film mulching used 33.5% and 34.1% more water than the CK in the two years, respectively. Of the mulching methods evaluated in the study, the whole field plastic mulching without soil cover and bunch-seeding achieved the highest grain yield and WUE, and also highest water consumption. Due to the large amount of water consumption with plastic film mulching, the water storage in the 0-200 cm soil layer at harvest was significantly lower in the fields with plastic film mulching compared to the CK. However, due to the year-round continuous plastic mulching coupled with the recharge of soil water during the summer fallow period after winter wheat harvest, the water storage in the 0-200 cm depth in the fields with plastic film mulching exceeded that in the CK field by 41.8 to 86.4 percentage points by the autumn sowing date the following year. Plastic film mulching and soil moisture conservation during summer fallow period is beneficial to the rehabilitation of soil moisture and sustainable production of the crops the following year. Among the plastic film mulching methods, the whole field plastic mulching with soil covering on the top of the mulch and bunch-seeding gained the highest economic benefit, and reached up to 5531 Chinese Yuan/hm^-2, which was 2542 Yuan more than the CK. Additionally, the whole field plastic mulching with soil cover on the top of the mulch and bunch-seeding allows the plastic film to be reused for the crops grown in the following year, helping save film cost, and improving economic benefits. Therefore, we recommend that whole field plastic mulching with soil cover on the top of the mulch and bunch-seeding is suitable to be popularized in the semiarid rain-fed areas.