Abstract: The research on the method of smoke exhausted in sloping tunnels is helpful to the rescue and escape for crew in the tunnel fire． In order to explore the method of smoke exhausted in the tilted tunnel fire under the condition of semi-transverse ventilation，the numerical simulation is adopted to simulate the process of tunnel fire in this paper，and then analysing the rule of the coefficient of λ (uniformity coefficient of smoke exhaust range) and α (the thermal efficiency of smoke exhaust) in different smoke-exhaust methods． Ｒesults show that when the slope is 0. 0% ～1. 5%，the standard of smoke exhaust can control the smoke to spread effectively in the tunnel; When the slope is 1. 5% ～3. 0%，smoke along the down-slope direction can be controlled near to exhaust port due to the effect of buoyancy，so the method of unilateral smoke exhaust in the upslope direction is adopted to exhaust effectively and improve heat effi-ciency of smoke exhaust of fans; But when the slope is more than 3. 0%，the smoke exhaust rapidly escape from ex-haust port and spread to the tunnel exit because of the chimney effect which makes the smoke exhaust in the tunnel spread with tremendous speed，so longitudinal ventilation should be added to restrain the reflux of smoke exhaust in the upslope direction，which restricts the spread of the smoke exhaust more effectively．

Key words: tilted tunnel fire, semi-transverse ventilation, heat efficiency of smoke exhaust, well-distributed effi-ciency of smoke exhaust