Belt conveyor has played an essential role in underground coal transportation. However, due to long-distance transport, it facilely confused ventilation system. Furthermore, once belt fires occurred, the accident would be spread to other areas rapidly. Numerous toxic and harmful flue gases would flow along the roadway, which posed a significant threat to the safety of underground miners. In this research, the ventilation system in Wangjialing coal mine, Hejin City, Shanxi Province, China which was taken as the object to investigate how to control the spread of flue gases by the disaster-relief dampers, when the fire happened in belt conveying roadway. The air-quantity could be achieved before and after the adjustment of local ventilation system by the ventilation network calculation. Furthermore, airflow velocities markedly impacted on the belt fire in the roadway in the 20102 face, conducted by the FDS software. The results indicated that an effective method to control the spread of flue gases was install11 disaster-relief dampers in the underground connecting roadways which located among belt-conveying roadway, main return airway, and auxiliary-transport roadway. When the wind speed was about 2.5 m/s, the effect of exhaust smoke was better in the roadway of 20102 working face. The direction of flue gases changed observably after adjusting local ventilation as the disaster relief dampers. Most flue gases went into the main return airway, the quantity of flue gases significantly decreased flowing to the working areas. Therefore, the short circuit and the open circuit for air flow achieved by governing ventilation system as disaster relief dampers was significant for the control of areas flue gases spreading.