“5.12” Wenchuan earthquake ，“8.18” debris flow，“4.20” Lushan earthquake and other large-scale geological disasters made additive effects on the study area, and constituted a unique engineering geological environmental condition. Through systematically investigate and collect geological prototype research of the debris flow material source before and after Lengmugou earthquake, Baoxing country and first-hand information of debris flow disaster prevention and control, the point research of the source condition of debris flow and comparative research before and after the "4.20" Lushan earthquake debris flow material source characteristics, dynamic and static material source reserve ratio, according to material source is one of the three conditions formed debris flow. The analysis results indicate that Lengmugou point material source, line material source and surface material source has well-developed, but the major is gully erosion source material (line material source), reaches 76.110% and 60.690% before and after earthquake. After Lushan earthquake, during the accumulation material source in shore ditch (point material source) increased exponentially, ratio of 48, by more than 31.490%.In addition to ditch shore erosion source material source (surface material source), dynamic reserves than before the earthquake source in the same watershed section. Static and dynamic material source reserves of linear relationship is relatively obvious, the correlation coefficient (R2) of 0.8 ~ 1.0, are positively related, and is highly relevant.