【Objective】In this study, effects of dry-wet alternation on diversity, abundance and structure of the soil microbial community in the black soil of a long-term stationary field experiment in Dehui of Jilin on tillage modes, no-tillage or ridge tillage, were investigated. So far few reports were detected in the literature about responses of the soil microbial community in the soil subjected to drying-wetting alternation under no-tillage or ridge tillage. In this paper, soil samples were collected for analysis by means of high-throughput sequencing in laboratory. This research was expected to be of great significance to prediction of impacts of drought on soil functions under different tillage practices. 【Method】No-tillage and ridge tillage plots in the field experiment had been cultivated with maize (Zea mays L.) for 13 years. Soil samples were collected with a T sampler, ground to pass a 4-mm sieve, and then packed separately into PVC pipes with a sealing film at the bottom of each pipe to make the soil in the pipe the same in bulk density as that in the plot under no-tillage or ridge tillage. The amount of soil packed into the pipe for no-tillage was 115.75 g and for ridge tillage, 113.04 g. Five dry-wet treatments different in frequency and intensity were designed and implemented: (1) CK as control; (2) MDW1, one round of moderate dry-wet alternation; (3) VDW1, one round of very dry-wet alternation; (4) MDW3, three rounds of moderate dry-wet alternation; and (5) VDW3, three rounds of very dry-wet alternation. Soil microbial communities were investigated by means of Illumina Miseq sequencing. Soil available phosphorus and available potassium were determined with conventional analysis methods. Soil pH was determined with a composite electrode. And soil water ratio was set as 1:5. For measuring carbon and nitrogen, a part of each treated soil sample was ground to pass a 0.85 mm sieve. Total carbon and total nitrogen of the soils were determined with the Vario Max produced by the German Elementar Company. 【Result】Results show that dry-wet alternation significantly reduced microbial diversity in the soils under no-tillage, and the effect was amplified with rising frequency and intensity of the dry-wet alternation. However, dry-wet alternation did not affect microbial diversity in the soils under ridge tillage. Compared to the control, the treatments under dry-wet alternation significantly increased the relative abundances of Planctomycetes and Verrucomicrobia in the soils under no-tillage and significantly reduced the relative abundances of Saccharibacteria and Parcubacteria in the soils under either no-tillage or ridge tillage, and increased the relative abundance of Gemmatimonadetes in the soils under ridge-tillage. Relative abundances of Proteobacteria and Acidobacteria were significantly lower in the soils under ridge tillage than in the soil under no-tillage, while that of Actinobacteria was significantly higher in the soils under ridge tillage. Relative abundances of Firmicutes and phyla in the “Others” did not vary much between the two tillage modes. Frequency of dry-wet alternation did affect structure of the soil microbial community. However, intensity of drought in the treatments did not have much effect on structure of the soil microbial community. So soil microbial community structure is significantly altered by frequency of the alternation, but not by intensity of the drought in the dry-wet alternation. Redundancy analysis was conducted with available phosphorus, readily available potassium, total N, total C and pH of soil as explanatory variables and 11 phyla of microbes in the soils under no-tillage and ridge tillage as response variables. Readily available potassium was the main environmental factor affecting the distribution and quantity of soil microorganisms. 【Conclusion】Dry-wet alternation has certain significant effects on soil microbial communities, but such effects are dependent on tillage practices and frequency of the dry-wet alternation. This study is expected to provide a theoretical basis for predicting effects of arid climate on soil ecological functions.