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.