Abstract: The Cyber-Physical System (CPS) has been highly concerned since it was proposed. However, the key of creating a good CPS system critically depends on the prophase design of the system model. Currently, it has become the focus and difficulty of research at home and abroad that models a CPS system with comprehensive, robustness, security. According to the previous studies, the CPS system was divided into computing entity, physical entity and control entity. A modeling method of computation entity of CPS was provided, which is DBM-UML (Dynamic behavior modeling-UML). With this method, an analysis of the entire system's structure was given firstly and the corresponding state machine was abstracted. In another word, the system was modeled firstly by the dynamic behavior modeling of the state machine. Then the detailed modeling of the computation entity of the system by the UML modeling language was proposed. The logical relationship and feedback mechanism of the system were proposed and the system was modeled better.

Key words: CPS, UML, dynamic behavior modeling, state machine