In order to reveal the effect of returning farmland on the soil infiltration characteristics of the outcrop rock-soil interface in the rocky desertification area, the arable land was taken as the control, and the fallow field, farmland return to shrubs grassland and orchard were selected as the research objects, and the soil infiltration characteristics of rock-soil interface with different shapes of straight, convex and concave were studied through the ring knife method. The results showed that: (1) The soil infiltration process and characteristics at the rock-soil interface of different types of returning farmland varied greatly. From the initial infiltration rate to the stable infiltration rate, the attenuation range was between 0.350 mm/min and 55.756 mm/min, and the soil infiltration rate varied greatly among different rock-soil interface shapes. (2) The main influencing factors of soil infiltration rate at rock-soil interface of different types of returning farmland were capillary porosity and non-capillary porosity. The initial infiltration rate, average infiltration rate and stable infiltration rate all had extremely significant negative correlation with capillary porosity (p＜0.01). The initial infiltration rate was significantly positively correlated with non-capillary porosity (p＜0.05). (3) Compared with Kostiakov model and Philip model, Horton model had the best applicability for fitting the soil infiltration process at the rock-soil interface of different types of returning farmland, and it could better simulate the soil infiltration process and predict the soil infiltration capacity. (4) According to the principal component analysis, soil infiltration capacity at the rock-soil interface followed the order of arable land (0.99)＞fallow field (0.16)＞returning farmland to shrubs and grassland (-0.43)＞returning farmland to orchard (-0.72). The returning farmland significantly reduced the soil infiltration capacity of the outcrop rock-soil interface in the rocky desertification area, especially at the convex rock-soil interface. The research results were expected to provide a scientific basis for future understanding of the water leakage at the rock-soil interface in rocky desertification areas after returning farmland.