Abstract: In order to explore the effect of whole mineral anti-reversing speed on the spread of chamber fire smoke, the 3D model of roadway was constructed by using FDS fire numerical simulation software, the fire scenes under four conditions were simulated, that was, when the whole mineral anti-reversing speed was 1.0 m/s, 1.5 m/s, 2.0 m/s and 2.5 m/s respectively. Comparing the changes of smoke concentration on both left and right side of the chamber and the visibility in the tunnel under different air-reversing speeds. The results show that when the whole mineral anti-reversing speed is 1.0 m/s, the wind flow on the inlet side of the tunnel is in disorder, and the smoke has obvious recirculation flow; with the increase of the air-reversing speed, the direction of wind flow on the inlet side begin to reverse, and the visibility in the tunnel and the air-reversing speed continue to increase; it is suitable when the air-reversing speed is 1.5 m/s to 2.0 m/s, and when taking rescue measures for the chamber fire accident, the air-reversing speed should be ensured to be greater than the critical wind speed of 2.5 m/s.