The paper briefly describes the research status of the data lifecycle of wearable medical and health devices and analyzes a representative case. In addition, the data flow path has been analyzed from five aspects:data collection, data transmission, interoperability, data integration, data management and verified combined with the representative case-G5 Mobile Continuous Glucose Monitoring System. Finally, it is found that the problem of data multiplexing and exchange, data privacy security and protection in the process of the data flow of wearable medical and health devices.