Abstract: Objective Discuss the working ideas of the dynamic adjustment mechanism of medical device classification in the United States, and provide reference for the construction of medical device related mechanisms in China. Methods Collect and interpret the documents of regulatory background, procedures and orders of the dynamic adjustment mechanism of the medical device classification in the United States, and summarize the overall situation and specific cases of the medical device classification adjustment under this mechanism in recent years. Results The US work idea of the medical device classification dynamic adjustment mechanism is based on the latest valid scientific evidence, conducting risk analysis and identification, and determining the corresponding measures. Conclusion During the adjustment process, industry stakeholders have repeatedly discussed and achieved final agreement. Its procedures and working ideas can be used as a reference for China's work.