Abstract: In order to perfect the theoretical system of safety systematics, the theoretical models of system safety synergy were constructed from the perspective of “flow”. Firstly, the concept of “flow” in system safety was put forward and its characteristics and classification were analyzed. Secondly, the synergy ideas of system safety “four flows” (namely material flow, energy flow, information flow, and behavior flow) were summarized and the conceptual model of “four flows” synergy for system safety was constructed. Finally, the system safety analysis model based on “four flows” synergy was developed and its connotation was explained. The results show that “flow” possesses four properties, that there are different types of flows under different system safety dimensions like essential factors and radiopacity, that the proposal of system safety “four flows” synergy and its modeling can be achieved from safety natural science and safety social science path, and that system safety “four flows” synergy is a new analysis thought and method for system safety.

Key words: safety systematics, system safety synergy, material flow, energy flow, information flow, behavior flow