This research was based on the ecological problems of granite red soil in South China, such as the coarse texture, poor physical properties, serious soil erosion and so on. In order to reveal the effects of SAP application on slope erosion of granite red soil, a simulated rainstorm experimentwas conducted. SAP was applied with three methods:layering (K1), furrowing (K2), mixing (K3) application. The results showed that:(1) Under the application of SAP, the initial runoff production time of granite red soil slope was 1.09~1.61 times longer than that of the control. The orders of infiltration rate and the water contents were K2 > K3 > K1 > CT and K3 > K1 > K2 > CT respectively. (2) The order of flow reduction rate was K3 > K2 > K1, and the sediment reduction rate was shown as follow K2 > K3 > K1. Compared with the control slope, the cumulative runoff and sediment yield in mixing treatments decreased by 59% and 66%. The mixing treatments achieved the better benefits of soil and water conservation in this research. (3) Under the different treatments, the cumulative runoff and sediment yield formed a power function model on the granite slope of red soil, and the correlation coefficients were all greater than 0.990. The findings provided theoretical basis and practical references for the study on the granite slope of red soil.