In order to improve the weak points of traditional supply chain management (SCM), in the paper the concept of supply and demand network with multi-functional and opening characteristics for enterprise (SDN) is put forward. Then, the requirements and characteristics of dynamic business structure in the environment of SDN are analyzed. Finally, a dynamic business structure and its coordination model based on Multi-agent theory are established. In the structure and its model, the systematic units bear the abilities of intelligent decision-making, autonomy, self-organization, and coordination, which supports the dynamic business re-structure and provides the enterprises with the ability of adapting to rapid external changes by means of swift internal changes.