Abstract: A main fan monitoring system based on inverter control is designed. This paper introduces the working principle and working mode of data exchange between the inverter and the main controller. This paper analyzes in detail the problems and basic principles in the data exchange from the aspects of the monitoring mode of the master controller, the control mode of the inverter, the function setting of the inverter, and the external wiring of the inverter. The problem of stepless speed regulation of inverter in the demand is analyzed deeply, and the solution is provided and implemented.