Buffer zone set between aisle and anteroom is proposed to improve the traditional mode of pressurizes mechanic smoke extraction. Fire Dynamic Simulation is used to simulate the model of high-rise fire. Eight models are set and analyzed

in which the smoke temperature distribution and concentration distribution are compared

and the best parameters is worked out. The result shows

when exhaust smoke volume is constant

the velocity of air curtain is as low as possible; when the volume of air curtain is constant

the smoke volume is as low as better. Based on the comparison

it is found that the smoke removal efficiency of mode 4 is the best one

which is about 74.06%. The evacuating buffer not only can let smoke out timely

but also can guarantee safe personnel evacuation.