Abstract: At present most of the researches on wireless sensor network focus on the protocols at different levels, network security, QoS and power control. However, the topological structure of network as the basis of the upper algorithm plays a decisive role in the performance of wireless sensor networks. The spatial multiplexing caused by the change in the topological structure of wireless sensor networks is described, with the spatial multiplexing ratio quantified. Then the characteristics of network connection topology of wireless sensor networks are proposed. As a result, an important reference is provided for the design of a dynamic network MAC protocol.