建筑火灾中轰燃现象是一种典型的突变过程。本文利用数学方法推导出轰燃的突变动力学,首先给出基于能量平衡方程的轰燃模型并构建其突变簇方程,然后讨论系统控制因子和实际工况之间的关系。结果发现建筑火灾中轰燃现象的突变形式是燕尾突变。 Phenomenon in the building fire flashover is a typical mutation process. In this paper, we deduced the sudden change dynamics of the flashover by mathematical method. Firstly, we give the flashover model based on the energy balance equation and construct its abrupt cluster equation, and then discuss the relationship between the system control factor and the actual working conditions. As a result, it was found that the mutational form of the phenomenon of flashover in a building fire was a dovetail mutation.