Abstract: In the actual mining production process，the belt fire is usually affected by many factors.The fire dynamics simulation software PyroSim was used to establish simulation model and determine the real characteristics of the fire and the factors affecting the fire evacuation in this paper.The changes of temperature，smoke concentration and visibility in tunnel during belt fire were simulated over time in Shenjiazhuang mine.From the simulation results，we found that the key factors influencing the fire evacuation were gas temperature，CO concentration and visibility.Simulation results show that the first 200 seconds is the critical escape period of workers in the fire leeward during the mine belt fire，and 400 seconds later，high temperature flue gas，high concentration of CO and low visibility will seriously affect personnel escape.The results provide a reference for mine emergency rescue and fire evacuation.