基于人群流动理论和离散计算方法对传统疏散时间计算公式进行了改进，并提出了疏散离散时间计 算模型（EDTM）。运用此改进模型对天津奥林匹克中心体育场某看台出口人群疏散时间计算，并与 BuildingEXODUS计算机模拟、传统公式计算结果对比分析表明，此改进模型计算结果与计算机模拟结果非常接 近，且比传统疏散时间计算公式更为精确和符合实际情况，可代替传统疏散时间计算公式用于体育赛场尤其是 北京奥运赛场人群疏散时间计算及进行赛场性能化设计的依据。

In this paper, a computational evacuation discrete time model(EDTM) has been presented to analyze the building egress evacuation time problem with previous works, and discusses the advantages of the use of the modified model over the use of the previous model. EDTM uses crowd flow theory and discrete computational methods to identify various width of egress that are available to the occupants for movement,  which is more accurate and practicable because the crowd flow rate is variable, while the crowd flow rate as the function of crowd density based on the empirical relations between density and velocity of crowd movement. A case of stadium stand egress is chosen for the validity of EDTM, and a comparison of EDTM with previous model and computer simulation indicates that both the EDTM and the simulation curves are found to give better predictions than the previous model. Based upon the results, EDTM shows great value in dealing with stadium,  especially the2008Beijing Olympic stadium, evacuation time calculation, egress performance design, selecting and optimizing of routes and so on.