The aim of this work was to study the existing support capability of an emergency material collection point under conditions of dynamic usage of emergency material resource. The definition, characteristics and influencing factors of support capability of emergency material collection point were clarified firstly, and then an expression model of dynamic support capability was established through the analysis on the support capability components and their interaction. And the effectiveness of the model was verified through a simulation instance. The existing support capability at any future timing of an emergency material collection point tasked could be evaluated well by the model based on the comprehensive occupation of various resources in the time ranges. The model is suitable for tasking for any emergency material collection point which is under conditions of sustained undertaking support task, and could increase the reasonability and feasibility of the decisions made for the selection of emergency material collection point and the collection amount.