For the problem that how to choose the network structure in smart home applications of Zigbee network, the paper proposes a scheme of using different network topologies for different node sizes and load. On the basis of the analysis of three different network topologies, the focus of analysis is that simulating the delay and throughput of the network performance parameters of MAC layer through changing the node size, network load and ACK mode by using opnet network simulation software in non-beacon enabled transmission mode. The experimental results show that network performance is greatly improved by employing different network topologies targeted which provides a theoretical basis for deploying appropriate network structure better in smart home applications.