Soil microbes are sensitive indicators for characterizing the quality of soil. In this study, Illumina HiSeq was used to analyze the effects of different mulching patterns on the microbial community structure and diversity of semi-humid dryland farmland soil in order to evaluate the impacts of these mulching measures on the soil quality from a microbial perspective. The soil microbial communities were tested under three different mulching patterns comprising film mulching (P), straw mulching (S), and ridge and furrow mulching (R), with conventional tillage without mulching as the control (CK). The relationships between the soil physical and chemical characteristics and microbial communities were analyzed. The results of the study indicated that each mulching treatment significantly changed the soil microbial community structure and diversity. The dominant phyla of bacterial in the soil samples among all treatments were Proteobacteria, Acidobacteria, and Actinobacteria with abundances of 29.69%, 28.28%, and 20.76%, respectively. Actinobacteria had the highest relative abundance under CK, but a high soil pH and low NO₃-N content inhibited the growth and reproduction of Acidobacteria in the soil. The dominant phyla of fungi were Ascomycota and Basidiomycota with abundances of 59.65% and 20.96%, respectively. The low soil temperature under the S inhibited the growth and development of Basidiomycota, and its relative abundance was the lowest among all treatments. Compared with CK, P and R significantly increased the diversity and richness of soil bacteria, while S and R significantly increased the soil fungi diversity and richness, and P had no significant effects on the soil fungi diversity and richness. Spearman's rank correlation coefficients showed that the soil bacterial diversity was mainly affected by the soil moisture(SM) and nitrate nitrogen contents(TN), and the soil fungi diversity was mainly affected by the soil temperature(ST), total nitrogen, and nitrate nitrogen(NO₃-N). Redundancy analysis showed that the microbial community structure was affected mainly by the soil moisture, soil temperature, nitrate nitrogen, and total nitrogen. In general, the diversities and abundances of soil bacteria and fungi were significantly higher under R than CK. The relative abundances of Basidiomycota and Glomeromycota were the highest under R in all treatments. The ectomycorrhiza and secondary mycorrhiza formed by these phyla can enhance the absorption of root nutrients as well as improve the stress resistance by crops. The results showed that the crop yields were the highest under R. Ridge and furrow mulching is recommended as the planting method in this semi-humid dry farming area.