：The conventional monitor mode of intensive crowd depends primarily on manpower or video surveillance, which employed to manage the crowd to prevent stampede is very difficult to implement effectively. For the purpose of judging the state aggregation of pedestrian in time, in this paper the correction coefficient is presented by comparing the measured with the mobile phone location data, based on mobile phone positioning technology to make the implementation of monitoring and alert classification of dense population more practical, in 2015 Beijing Ditan Temple Fair. Furthermore, through the numerical simulation analysis of evacuation of the BaiTai of Ditan' crowd, the reasons of delay time for evacuation have been found out as well as the advancement of supervision. This research method and the conclusion in this paper can be applied for early warning and forecast of preventing the stampede on crowded places and safety evacuation. Research Background Along with continuous economic and social development, acceleration of urbanization and gradual prosperity of commercial and trade activities, the risk of stampede accident resulting from dense crowds has been increasing, and the safety management of dense crowds has become more difficult. The conventional monitoring mode of intensive crowd depends primarily on manpower or video surveillance, which makes it very difficult to carry out real-time all-round monitoring in densely-populated areas with multimode vertical-crossing walking facilities and complicated internal distribution. Traditional on-site monitoring merely plays the role of alarming for disposal, and lacks the forecasting and early-warning of dense crowd risk, therefore making it difficult to attain the goal of "prevention beforehand". Therefore, it appears very necessary to set up a set of dense crowd risk monitoring and early-warning system by using the mobile phone location safety technology, judge the aggregation state of pedestrians in time, and control the behaviors that may give rise to risks. At present, the theory of mobile phone network location is relatively mature. By collecting mobile phone network location data and connecting the path matching algorithm, we can acquire the travel tracks of mobile phone users, including travel time, average speed and travel distance information. By making full use of Internet, database and GIS technology, we can collect and analyze various key protected targets, danger sources and emergency data of cities, timely and effectively assemble various resources, carry out emergency measures, and offer assisted decision-making to emergency command, so as to reduce the threats of emergencies to resident health, property and life safety, perfect the emergency reaction mechanism of government to public emergency events, and set up an all-round "safety network" of emergency early-warning and treatment for cities. The collection technology of traffic information based on mobile phone location has aroused the universal attention of many domestic and overseas scientific re...