The solution against drought and cold in spring was one of the most important factors which increased the yield of spring wheat in northwest of Loess Plateau (104°36′E, 35°35′N). The objective of the study was to evaluate the effects of micro ridge-furrow with plastic mulching (PRF) on soil temperature and moisture at the seedlings stage and the regulative mechanism of PRF on soil thermal-moisture and photosynthesis of spring wheat. The field experiments had been conducted using Longchun 35 from 2016 to 2018 in cold rain-fed area of northwest Loess Plateau. The three treatments were: 1) micro ridge-furrow with whole field plastic mulching (PRF), 2) whole field soil-plastic mulching (PMS), and 3) without mulching (CK). The parameters including soil temperature, soil water content, above-ground biomass, leaf SPAD, photosynthetic and transpiration rate, the soil water storage (SWS), periodical evaportranspiration (ET), growth rate, and water use efficiency (WUE) were measured at 18, 25, and 32 days after sowing (DAS), respectively. The results were as follows: the mean soil temperature within 0-25 cm profile treated with PRF and PMS compared with CK, was increased by 3.6°C, 3.0°C, 2.0°C and 2.9°C, 2.5°C, 1.7°C respectively, while those treated PRF compared to PMS increased by 1.3°C, 0.9°C, 0.9°C and 0.8°C, 0.7°C, 0.7°C within 0, 5, and 10 cm profile at 18, 25, and 32 days. The SWS treated with PRF and PMS compared to CK was on the rise by 7.3, 9.7, 12.6 mm and 3.9, 7.6, and 11.0 mm within 0-40 cm profile at 18, 25, and 32 days, respectively. While those treated PRF within 0-40 cm profile with 10 cm intervals compared to PMS risen by 1.1, 0.9, 0.8, 0.6 mm. The parameters treated with PRF and PMS at seeding stage including plant biomass, growth rate, leaf SPAD value, net photosynthetic rate and transpiration rate were significantly higher than those of CK, while those of PRF higher than PMS. Moreover, the yield and WUE of PRF were increased by 9.1%, 36.5%, and 5.9%, 30.8% than those of PMS and CK, respectively. Therefore, the treatment of PRF and PMS could effectively improve the ability of photosynthesis and plant growth by overcoming the cold and drought situation at the seedling stage, and PRF treatment was more effective than PMS.