Abstract: Preferential flow caused by cracks area have resulted in severe water content reduction of the surface soil, destruction of vegetation, and limited land restoration in the coal mining subsidence. In order to understand the influence of cracks width on preferential flow, preferential flow characteristics of different widths of cracks were comparatively analyzed and quantitatively evaluated in a coal mining subsidence area along the middle reaches of the Yellow River. The analysis based on the staining tracer experiment, combined with the software such as Adobe Photo shop 2020, Image Pro Plus 6.0, and preferential flow characteristics of different widths cracks in the coal mining subsidence area (no crack and 3mm, 1cm, 3cm and 3.5cm wide cracks) were analyzed, and the development of preferential flow under different crack widths was quantified by the characteristic indexes of average substrate flow depth, stained area ratio, preferential flow ratio, length index, average maximum stained depth, and the coefficient of variation of the stained area ratio condition. Soil water movement in the non-cracks zone was dominated by substrate flow, and preferential flow development was evident in the cracks zone. As cracks width increased, the depth of preferential flow increased. For soil profiles at the same depth below the surface, the wider of the cracks stained, the greater of the area ratio, the more significant of preferential flow development. The range of matrix flow in the un-crack area was significantly greater than in the cracks area for the same amount of water seepage. For the cracks zone, there was less variation in the range of substrate flow under different widths cracks. Influenced by the orientation and morphology of cracks below the surface, the preferential flow has different transport ranges and morphology in each profile. The evaluation index of the crack area was larger than that of the non-fcrack area, and the presence of the crack promoted the development of preferential flow. The width of cracks in the coal mining subsidence area had significant effect on the depth of preferential flow, and the development of preferential flow was not only affected by the width of cracks, but also