Abstract: Catalytic combustion methane sensors are high power consumption. The wired gas concentration monitoring system has high installation cost, poor scalability and flexibility and heavy maintenance workload. In order to solve the above problems, a low-power distributed gas concentration monitoring system based on LoRa is designed. Moreover, the software and hardware design of gas concentration collection nodes and LoRa intelligent gateway are discussed in details. The gas concentration collection nodes use the STM32L151 ultra-low-power series processor. The system power supply is divided into three controllable parts through the power management module, and the power consumption is reduced through the power control strategy. ① The microcontroller core system adopts a low-power mode. ② MJC4/2.8J methane detection carrier catalytic element adopts dynamic energization to reduce the average current. ③ The modules in the collection nodes other than the microcontroller core system are powered on demand. The LoRa intelligent gateway uses the embedded real-time operating system μC/OS-II for task scheduling to optimize the performance of the gateway and improve CPU utilization. The test results show that the gas concentration collection nodes have good data transmission performance and the power consumption control strategy can reduce the average current of the collection nodes effectively, thus extending the battery life and reducing the system maintenance workload.