Abstract: In order to explore the influence of different evacuation stair design modes on evacuation, five evacuation models were constructed, and the numerical simulation method were used to compare and analyze the correlation between different stair forms and the number of stair transition platforms and evacuation efficiency. The results indicate that the form of stairs and the number of conversion platforms are directly related to the average evacuation distance of people in the buildings, the efficiency of people evacuate to the stairwell and the efficiency of people evacuate to the outdoor. The average evacuation distance is the shortest when the 4 stairs are scattered and no transfer platform is provided in the stairwell. The evacuation efficiency of all people step into the stairwell is the highest when 4 stairs are scattered and 2 transfer platforms are provided. The evacuation efficiency of all people step to the outside is the highest when 4 stairs are scattered and 1 transfer platform is provided.

Key words: protected stairway, evacuation efficiency, simulation