[Objective] The effect of surface cracks caused by coal mining on soil moisture changes in a loess-covered area was studied in order to provide data support for the study of soil moisture changes in coal mining subsidence area. [Methods] The study was conducted in a coal mining subsidence location in a loess-covered area. A self-developed mining subsidence surface crack simulation device was used to carry out physical simulation experiments. Soil moisture sensors were set around the cracks to analyze the characteristics of soil moisture changes caused by surface cracks. Hydrus software was used to build the hydrological models and to optimize them using the results of physical simulation experiments. The control variable method was used with the optimized model to calculate the differences between soil moisture content around surface cracks and soil moisture content in non-deformation areas under different fracture shapes, topography, and initial water contents. [Results] Crack width mainly affected the maximum crack-induced soil moisture loss. Crack depth mainly affected the location of the maximum crack-induced soil moisture loss. There were differences in the influence of cracks in the uphill direction and in the downhill direction. The larger the slope was, the more obvious the differences were. The smaller the initial soil moisture content was, the smaller the soil moisture disturbance by cracks was. When the initial soil water content was less than 20%, the impact of surface cracks on soil moisture was less than 15 cm away from the crack. [Conclusion] Under the same boundary conditions, the soil moisture simulation results were consistent with the changes observed in physical experimental results. The optimized hydrological model could be used to quantitatively analyze the disturbance characteristics of soil moisture resulting from surface cracks in loess-covered areas.