In this paper, five different tillage measures were designed, including conventional use of N fertilizer (FN), FN combined with corn straw returning (FNS), high application rate of N fertilizer combined with corn straw returning (HNS), reducing topdressing N fertilizer to basal (RN), reducing topdressing N fertilizer to basal combined with corn straw returning (RNS). Correlation analysis and path analysis were used to further disclose the changes and coupling effects of soil physiochemical and biological properties. Compared with no straw returning (FN, RN), straw returning (FNS, HNS, RNS) significantly increased soil water content of 0-100 cm soil, and the synergistic effect of straw returning and full film ridge cultivation (FNS, HNS, RNS) was stronger than that of single plastic film mulching (FN, RN), which provided more suitable hydrothermal environment for the normal decomposition of straw. Compared with FN, treatments with straw returning significantly increased the contents of soil organic matter and total nitrogen, and the effects of RNS and HNS were the most significant. The activities of catalase, urease, sucrase and alkaline phosphatase as well as microbial biomass carbon and nitrogen in soil increased significantly, the activities of catalase, urease, sucrase and alkaline phosphatase were higher in 0-20 cm soil than in 20-40 cm soil, and there was no significant difference between FN, RN and RNS treatments. Soil microbial biomass carbon and nitrogen were significantly or extremely significantly positively correlated with soil enzyme activities and soil carbon and nitrogen, and soil microbial biomass carbon and nitrogen were sensitive to the changes of soil organic matter, sucrase, total nitrogen and catalase, which could indicate the changes in soil properties. Compared with FN, corn yields of FNS, HNS and RNS increased by 5.30%, 10.93% and 11.41%, respectively, and the higher partial productivity of N fertilizer could be obtained with the conventional input of N fertilizer. In conclusion, some topdressing N fertilizer used as basal fertilizer with straw returning can balance soil carbon and nitrogen budget, save cost, increase yield and nitrogen use efficiency, thus, it is a feasible technology model for straw returning in the Loess Plateau of Inner Mongolia.