Abstract: China has a vast territory and a changeable geological environment, so disasters are widely distributed, which are invaded by geological disasters all the year round, which brings great harm to the lives and property safety of residents in disaster-prone areas. The prevention and control of debris flow disasters is very important. To research and develop a debris flow disaster warning system has become a top priority. Given that the current difficulties in obtaining debris flow disaster data, insufficient data volume and low early warning accuracy, this paper designed a debris flow disaster monitoring and early warning system for data collection of debris flow impact factors and disaster early warning which introduced the optimal path forest algorithm to predict the probability of debris flow disasters. The test results show that the data collected by this system on the impact factors of debris flow disasters are accurate and reliable, and can accurately predict the occurrence probability of debris flow. It is very necessary to adopt a monitoring and early warning system in the prevention and control of debris flow disasters. This study provides a new idea for the prevention and control of debris flow disasters.