Collapses，landslides and debris flow are common disasters haunting the mountainous regions of Western China. In recent years，debates have been heard about the causes of geological disasters. Some believe that these disasters are mostly natural disasters，while others emphasize that human factors are not to be overlooked. Through case study on the debris flow in Zhouqu County in 2010，this paper analyzes the causes and explores methods for disaster forecasting and post-disaster reconstruction.