Abstract: The paper put forward a design scheme of monitoring and control system of water level of boiler steam drum based on CAN bus,and gave the overall structure of the system, at the same time, it expounded the design of hardware and software of CAN node controller. The running result showed that the system has performances of simple structure, reliable running and easy adjustment, which can improve the monitoring quality of boiler, increase the thermal efficiency of bioler and save energy sources and decrease pollution.