Medical interpreting has become a new research focus in recent decades, but few studies have discussed the role of interpreter in combination with strategies. This paper aims to work out how a medical interpreter plays his or her role and adopts strategies when interpreting between English and Chinese. Based on a first-hand medical interpreting corpus, this empirical study tagged the interpretation and made a detailed analysis of the interpreter's role and strategies. The results revealed that under the guideline of Goffman's participation framework theory the medical interpreter facilitated the therapeutic talk via three roles, namely “animator,” “author,” “principal”; for each role, different interpreting strategies, like “supplement,” “omission,” “compression,” etc. were adopted. Moreover, the study found motives behind interpreting strategies under the specific context. The sociological discussions are presented in the hope of enhancing medical interpreters' understanding of their roles and the importance of adopting more flexible strategies in order to provide better service.