The extensive use of dyed image analysis techniques in the research of soil preferential flow, optimization and improvement of dyeing image analysis methods, can promote in-depth study of the movement process of soil preferential flow, and quantitatively refine and analyze the developmental composition of preferential flow. Taking typical farmland sugarcane field as the research object, through field dyeing tracer experiment, using hue segmentation technology, combined with fractal and gray system theory, the preferential flow degree of sugarcane field soil in two typical farming methods (ridge and no-tillage) was quantitative analyzed and evaluated. The results showed that: under the same external water supply conditions, the preferential flow in the soil space of the ridged sugarcane field was scattered, clumpy and dot-like compared to the branch-like staining morphology of the no-tillage sugarcane field. The dyeing grade 1of the ridged sugarcane field, the fractal dimensions of 2 and 3 both decreased with the increase of soil depth. The preferential flow of "rapid change" in the top soil layer (0—10 cm) of ridged sugarcane field was 12.0 times that of no-tillage sugarcane field at the same depth, and the average percentage of preferential flow of "active" degree of no-tillage sugarcane field was 67.4%, which is 1.2 times that of ridged sugarcane land (54.2%). Bulk density had the greatest impact on the development of preferential flow in ridged sugarcane fields, and the degree of preferential flow decreased with the increase in bulk density. The saturated hydraulic conductivity of no-tillage sugarcane fields had the greatest impact on the development of preferential flow, and the degree of preferential flow decreased with decrease of saturated hydraulic conductivity. Ridge tillage affects the water content of sugarcane fields, speeds up the movement of water in the soil surface, reduces the development of deep preferential flows, reduces water infiltration, and can play a role in water storage and fertilizer preservation to a certain extent, can provide technical support for industry's production increase and increase related research of sugarcane planting in Guangxi.