Objective:To explore the effect of flipped classroom combined with case-based teaching method in the teaching rounds of orthopedic students. Methods:Medical trainee students who participated in the teaching rounds of orthopaedic sports medicine at the Chinese Academy of Medical Sciences and Peking Union Medical College from August 2020 to July 2021 were selected as the research subjects. Common sports injuries of the shoulder and elbow joints and meniscal injuries of the knee joint related to sports medicine knowledge were taught through traditional theoretical teaching and flipped classroom combined with case-based teaching. The after-class survey recorded the subjective perceptions of teaching effectiveness and objective theoretical test scores of trainee students,and compared the learning effect of the same group of students under the two teaching methods. Results:The number of medical trainee students who approved of the flipped classroom teaching method (13 cases) was significantly less than those who approved of the traditional teaching method (15 cases) (P>0.05). The scores of medical trainee students in the expanded thinking dimension of flipped classroom teaching method was higher than those of traditional teaching method,and the scores of in the confidence dimension of flipped classroom teaching method was lower than those of traditional teaching methods (all P<0.05). There was no statistically significant difference in the scores of the two teaching methods in the terms of self-evaluation,concentration,understanding and learning burden of the medical trainee students (all P>0.05). The scores of the four theoretical exams and total scores of the flipped classroom teaching methods were all significantly lower than those of the traditional teaching methods (all P<0.05). However,there was no statistically significant difference in the theoretical exam scores for the same teaching method (all P>0.05). Conclusions:In the teaching rounds of orthopedic sports medicine for medical trainee students,especially when the preview effect cannot be guaranteed,the flipped classroom combined with case-based teaching is as effective as the traditional teaching method in mastering theoretical knowledge. It is suggested that future teaching emphasize supervision and evaluation of pre-class preparation to improve the learning effectiveness and theoretical knowledge mastery of medical trainee students.