为了给建筑构件的耐火性能分级，必须要了解建筑构件的耐火时间。确定钢筋混凝土梁耐火时间以往只能通过耗资巨大的耐火试验。本文在一系列试验研究的基础上，建立了各种数学模型，提出一种分析法，采用计算机预测钢筋混凝土梁的耐火时间。这种方法的优点是能确定构件在实际火灾中的耐火性能。 In order to classify the fire resistance of building components, it is necessary to understand the fire resistance time of the building components. Determining the fire-resistance time of reinforced concrete beams can only be achieved through costly fire tests. Based on a series of experimental studies, this paper establishes various mathematical models, proposes an analytical method, and uses computer to predict the fire-resistant time of reinforced concrete beams. The advantage of this method is that it can determine the fire resistance of a component in an actual fire.