The invention relates to a microgrid monitoring system based on an OneNet platform and an implementation method of the microgrid monitoring system. The microgrid monitoring system comprises an equipment layer, a platform layer and an application layer. The equipment layer comprises micro-grid field equipment and wireless transmission equipment; the micro-grid field equipment comprises a photovoltaic power generation device, a wind power generation device, an energy storage device, a load control device and a central control device; the wireless transmission equipment comprises an NB-IOT wireless module and an MCU main control module; the platform layer comprises an OneNet Internet of Things open platform which is used for connecting the equipment layer and the application layer and is responsible for equipment access and development of an open interface auxiliary application layer system; and the application layer comprises a micro-grid monitoring system server end which is connected with the OneNet Internet of Things open platform and is used for remotely monitoring and managing the micro-grid. The Internet of Things open platform is introduced to the equipment end and the serverend, the difficulty of equipment access and application development in a traditional connection mode is reduced, the reliability and safety of the system are improved, and function expansion of the server end is facilitated.