In order to reveal the changes and impacts of the cultivable microorganisms number in farmland soil under different winter irrigation quotas in Shihezi during seasonal freeze-thawing period, a micro-field experiment was conducted during 2021—2022, the quantity changes of soil bacteria and mould and their influencing factors were analyzed under different winter irrigation quotas of 45, 90, 135, 180 mm with no-irrigation as the control during the freezing-thawing period. The results show that in the initial freezing period, the number of bacteria are significantly negatively correlated with soil water content and irrigation amount (P<0.05), while the number of mould is significantly negatively correlated with soil pH (P<0.05). In the stable freezing period, the number of bacteria are significantly positively correlated with soil average temperature (P<0.05) and significantly negatively correlated with irrigation amount and soil moisture content (P<0.05); while the number of mould is weakly correlated with soil moisture, temperature and salt. In the thawing season, the numbers of bacteria and mould are negatively correlated with soil water content (P<0.01), and the number of mould is significantly positively correlated with soil average temperature (P<0.05). Throughout the seasonal freezing-thawing period, bacteria are more dominant than mould, and play a major role in soil, and the effect of winter irrigation quota is not obvious on the numbers of bacteria and mold due to sufficient snowfall.