Brush is traditional used in realtime transmission of dynamic parameters of rotating machines,which is a contact part and limit to short life.The wireless communication method such as infrared,bluetooth and so on are susceptible to electromagnetic interference.A duplex communication system based on LiFi was proposed and the overall design of the system was discussed.The transmission efficiency and reliability of the data transmission were studied in which visible light was used as a carrier and a silicon photodiode was used as a receiver.The test results show that:the system supports 115 200 b/s baud rate of the USRT part,and the communication distance is up to 10 cm,which meet the data transfer requirements of most rotating components,and the system has the advantages of high stability,high speed,long life and low cost.