Abstract: Self-cleaning is a significant characteristic of debris flow open check dams, and this complex process is influenced by a number of factors, including the accumulation of debris flow in the reservoir, the opening of the dam and the intensity of rainfall.A total of 154 open check dams in Sichuan Province were selected to analyze the self-cleaning performance characteristics and effects based on a combination of site inspection and drone aerial survey.The results demonstrated that the number of beam dams, slit dams and slot dams in the study area was 22, 30 and 102, respectively.Additionally, the proportion of dams in the low occlusion rate was the largest, at approximately 41.6%.Self-cleaning can slow down the longitudinal slope and result in formation of a coarse surface of debris flow accumulation and the emergence of erosion grooves.A matrix of five levels: none, slight, medium, strong, and very strong, was constructed to evaluate the effects of self-cleaning in the reservoir, corresponding to 21, 44, 61, 26 and 2 dams.The key factors affecting the self-cleaning effect were the longitudinal slope of siltation, rainfall intensity and relative opening, which were significantly positively correlated with the self-cleaning effect.