The paper introduces the history of TRL (Technology Readiness Level) and its application in technology maturity assessment in the medical field, combining with the production, utilization and supervision characteristics of medical devices, it analyzes the security, validity and listing supervision problems of applying TRL to assess technology maturity of medical devices. The study also elaborates the TRL level definition and description proposed by US Department of Defense and NATO. It is feasible to apply TRL for technology maturity assessment of medical devices. TRL is an efficient R&D management tool and technology communication tool which can mitigate technical risks, assess R&D progress and accelerate successful development of medical devices.