Preferential flow is a non-equilibrium flow which presents the rapid movement of water and solute transport in soil. It has become a significant soil water movement type in special geological conditions of karst area. This paper concentrated on typical farmland of sugarcane field with smash-ridging and no-tillage types in the karst area of Southwest China, using the methods of brilliant blue dye, image analytics and the soil moisture layer evaluation to present the soil preferential flow features of two tillage types. The results showed that under the same water supply condition, the wetting front curve of sugarcane field with smash-ridging was more gentle than no-tillage field. The average infiltration depth of sugarcane field with smash-ridging was 0.05 times lower than that of no-tillage type, which presented homogeneous infiltration pattern. The preferential flow staining pattern of sugarcane field with two tillage types was scattered clumps (smash-ridging type) and dendritic patterns (no-tillage type), respectively. At the same external condition, the occurrence of preferential flow was faster in sugarcane field with no-tillage, which the rate of preferential flow was 1.45 times higher than the sugarcane field with smash-ridging. The average preferential flow fraction of sugarcane field with smash-ridging was 82.89%, which was lower than the no-tillage (88.61%). There was significant difference between them (P<0.05). Along with soil depth, the occurrence and change degrees of preferential flow in sugarcane field with smash-ridging changed from secondary active, active, secondary active, relatively stable, and to secondary active, while the change degrees of preferential flow in no-tillage type was higher, which changed from secondary active, active, secondary active, and to relatively stable. The occurrence of preferential flow in no-tillage type was mainly at depths of 5-35 cm, which was deeper than the smash-ridging type (10-30 cm). Compared with the no-tillage type, the smash-ridging type reduced the occurrence and change degrees of preferential flow in sugarcane field of karst area. The soil abilities of water and fertility retention were improved to a certain extent.