Abstract: A gas monitoring node based on wireless Mesh network is designed. Six parts of the hardware circuit is presented in detail, including the node battery power supply circuit, gas detection circuit, alarm circuit, display circuit, light control circuit, wireless network module, and the power consumption and work mechanism of all parts of the hardware circuit are presented in detail too. The simulation results show that the node realizes the wireless ad hoc network and low power consumption, and can ensure the gas monitoring node to work more than 7 days without changing the battery.