矿井火灾已成为矿山安全生产过程中重点关注的问题之一，尤其高原地区受制于复杂的环境因素，火灾时期的抢险救灾成为难题，因此研究海拔高度对火灾烟气传播规律的影响具有重要的实践意义。采用火灾数值模拟软件FDS，对5种不同海拔高度（0，1 000，2 000，3 000，4 000 m）下矿井巷道火灾进行动态模拟，通过观察烟气扩散和动态升温过程，分析不同海拔高度下烟气扩散和温度分布规律，并对比不同海拔高度下矿井巷道内温度、烟气行为（CO浓度）和能见度等参数的变化情况，据此分析海拔高度对矿井火灾时期人员安全疏散的影响。结果表明：火灾烟气蔓延速率随着海拔高度的增加而减小，且高海拔地区减小幅度更大；随着海拔高度的增加，火灾蔓延过程中产生的顶峰温度和CO浓度值均减小，且能见度增强，对人体产生的危害也相应减小。总体来说，当海拔相对较高的矿井发生火灾时，相较于正常海拔地区，安全疏散时间延长，安全疏散距离缩短，更有利于人员逃生。

In the process of mine safety production，frequent mine fire accidents have caused huge casualties and economic losses，which has become one of the major concerns.The environment conditions of mines at different altitudes are completely different，which directly affects the evolution of the mine fire，and brings great challenges to the emergency rescue work during the mine fire.Therefore，it is of great practical significance to study the effect of altitude on the law of smoke spread during the mine roadway fire period.In this paper，based on the construction of the mine fire model，the key paramaters of the fire smoke at the characteristic height of the human eye (z=1.6 m) were used as the focus，fire scenarios of the mine mechanical and electrical chamber at five groups of different altitudes from 0 m to 4 000 m（equal points） was simulated by using the Fire Dynamics Simulator（FDS）.By observing the process of smoke diffusion and dynamic temperature rise in different fire scenarios，the law of smoke diffusion and temperature distribution in mine roadway at different altitudes was analyzed.At the same time，the changes of temperature，smoke behavior（CO concentration），visibility and other fire smoke characteristic parameters in the mine fire at different altitudes were compared，so as to analyze the influence of altitude on the safety evacuation of underground personnel during mine fires.The results show that：（1）With the increase of altitude，the rate of smoke spread and the influence range of smoke in the mine fire are correspondingly reduced.In the transverse diction，the effective and safe evacuation route should be far away from the fire side in the tunnel；（2）With the increase of altitude，the characteristic parameters of fire smoke also change to some extent，that is the peak temperature and CO concentration decrease，while the visibility gradually increases；（3）Compared with low-altitude areas，when the fire occurs in the mine with relatively high altitude，the safety evacuation time is prolonged and the safety evacuation distance is shortened，which makes the possibility of people’s safety escape is greater.In general，this paper reveals the mechanism of the effect of altitude on the smoke spread of mine fire，which can be used as reference for the prevention and control of mine fire accidents.