Abstract: There are indoor artificial rainfall experiments in self\|designed model under different rainfall intensity (26 mm/h, 51 mm/h, 68 mm/h) to study the mechanism of loose deposit slope stability in the debris region. The results showed that the soil loss under low rainfall intensities of 26mm/h is least, and the failure mode of slope is slope surface erosion; but under high rainfall intensities of 51 and 68mm/h, both failure modes of slope are slope surface erosion and gully erosion, and flowslide is the main failure mode, which are correspond to the mutation point of curve of cumulative soil loss vs time. Intermittent debris flow is formed under high rainfall intensities of 68 mm/h.