Abstract: In order to investigate the influence of roadway slope on the smoke flow of fire in mine roadway during updraft ventilation, the fire dynamics simulation software Pyrosim was used to establish the flame propagation model of the roadway line and the effectiveness of the model parameters was verified based on the full-size roadway fire test conducted by Institute of Occupational Safety and Health in the United States. Based on the above parameters, a wind tunnel model with different gradients was established with the return airway of Chengzhuang Coal Mine in Shanxi Province, and the temperature and pressure fields generated during the fire were numerically simulated to analyze the temperature, pressure distribution and the spread of smoke inside the tunnel. The simulation results show that when the uphill roadway slope is increased during updraft ventilation, the initial rate of fire propagation can be accelerated, the critical wind speed to restrain the reverse flow of flue gas decreased. At the same time, the high-temperature fire area is shifted to the downwind side, the temperature decreases as a whole, and the pressure difference at the inlet and outlet increases.