Abstract: To meet the requirements of real-time performance, scalability, flexibility, and reliability in multi-module monitoring of inverter power supplies, a monitoring network was established using CAN fieldbus as the system communication transmission method to monitor the inverter power supply modules. Based on this, the design of the monitoring scheme on the operator station side is described, and the specific formulation of the CAN bus application layer protocol and the design and implementation of the communication software are highlighted. Communication between the operator station and the controller was realized, completing the monitoring function of the inverter power supply modules. Keywords: CAN bus; application layer protocol; monitoring 1 Introduction New high-frequency, low-power inverter power supply equipment utilizes parallel connection between power supply modules to achieve power synthesis, forming a modular, intelligent distributed high-power power supply system, which is a promising new technology. Combining several power supply modules can form power supply systems of any power level, with broad application prospects. Fully digital automatic control systems based on fieldbus are a hot topic in the field of industrial automation worldwide. This paper uses CAN fieldbus to build a monitoring network to monitor single-module and multi-module power supply modules of embedded intelligent controllers containing DSPs. CAN (Controller Area Network) bus belongs to the fieldbus category and is a serial data communication bus. The CAN bus architecture model adopts layers 1, 2, and 7 of the ISO/OSI reference model, namely the physical layer, data link layer, and application layer. The content of the application layer mainly depends on the user's needs; therefore, in practical applications of the CAN bus, users can implement the application layer functions as needed. For details, please click to download: Research and Application of CAN Bus in Inverter Power Supply Monitoring Modules.