Abstract: In order to guide farmland irrigation in winter and spring, a series of field infiltration tests during seasonal freezing-thawing period were conducted using two-ringer infiltration apparatus, and the effects of plastic film mulching on infiltration characteristics were analyzed. Results show that plastic film mulching on soil surface has obvious heat and soil moisture conservation effect; the soil covered with plastic film freezes late and thaws early, and soil water content has less change. In early and middle freezing period, the infiltration capacity of plastic film mulching plot is higher than that of bare plot, but it is in reverse case in the last freezing period and whole thawing period. During seasonal freezing-thawing period, the time that the minimum infiltration capacity of plastic film mulching plot appears, compared with the bare plot, is about 20 days later. The research results have practical and theoretical values for effective utilizing of soil water resources and reasonable guiding of irrigation in winter and spring in seasonal freezing-thawing regions.