The basic development environment of IAR is adopted for ZigBee software programming. After the system is powered on, the coordinator scans and selects an optimal wireless network. Each sensor will adopt the transmission mode of parent-child node. The coordinator node is the parent node, and other sensor nodes are the child node. The child node can send data and interrupt request to the parent node, and the parent node can send data to the child node. IEEE only deals with low-level MAC layer and physical layer protocol, while ZigBee alliance standardizes its network layer protocol and API, and ZigBee alliance also develops security layer.