[Objective] The object of this study is to reveal the effects of whole film casing mode bunch on soil microbial number and microbial biomass in dryland in order to provide basis for its popularization and application. [Methods] The field experiment was carried out to study the effects of different mulching methods on soil microbial number and microbial biomass at different growing periods of winter wheat. [Results] The whole film casing mode bunch increased soil microbial number and microbial biomass significantly in different growing periods of winter wheat. Compared with traditional planting methods, the whole film casing mode bunch(M₁) increased the amount of soil bacteria, actinomyces, fungi, ammonifier nitrobacteria and soil microbial biomass C and N by 32.07%, 31.27%, 44.56%, 32.54%, 79.20%, 29.90% and 29.41%, respectively. While the whole film without overburden bunch(M₂) increased the amount of soil bacteria, actinomyces, fungi, ammonifier, nitrobacteria and soil microbial biomass C and N by 10.23%, 10.57%, 26.51%, 37.85%, 107.22%, 20.68% and 18.02%, respectively. The amount of soil microbes and microbial biomass started to rise at the regreening stage, reached the peak at jointing or heading stage, and then decreased slightly at the later stage of growth in all treatments. [Conclusion] The amount of soil microbes and microbial biomass decreased with the increase of soil depths in the whole film casing mode bunch. Therefore, the whole film casing mode bunch could improve soil microbial number and microbial biomass.