By means of the field investigation, the study area and sample plant were determined in Bulianta coal mine of Shendong Area. And then soil samples in rhizosphere were collected before and after underground coal mining. Through the analyses on experimental data, the effects of surface cracks caused by underground coal mining on the rhizospheric microhabitat of Populus cathayana are analyzed. The results indicate that for the rhizosphere of Populus cathayana, in terms of quantity, bacteria, actinomycetes, and fungi are in a descending order. There is a significant distribution precept of the microorganism amount, enzyme activity, and water content of soil and pH value in different seasons. The surface cracks reduce microorganism quantities, enzyme activities, hyphal density, mycorrhizal infection rate, soil water content, and electrical conductivity of soil in the rhizosphere of Populus cathayana. With the time goes by, the effects of surface cracks on the rhizospheric microhabitat of Populus cathayana are gradually weakening.