Objective To explore the construction of online and offline multi-teaching methods and its influence on students’ academic performance and diagnostic ability in experimental teaching of diagnostics. Methods Ninety-eight clinical medical students were enrolled in this study. According to the random number table method, the studentswere divided into control group and observation group（n=49）. The control group adopted conventional teaching methods, and the observation group received online and offline multi-teaching methods. The students’ academic performance, diagnostic ability, academic self-efficacy, and teaching satisfaction were compared and analyzed. Results At the end of the semester, compared to the control group, the theoretical test and the practical test scores of the observation group were significantly higher（P<0.001）; the ability of medical history collection, doctor-patient communication ability, clinical diagnostic thinking ability, diagnostic analysis ability, and interest in learning significantly increased. The academic self-efficacy and teaching satisfaction of the observation group were significantly higher than those of the control group（P<0.001）. Conclusion The establishment and application of online and offline multi-teaching methods can effectively improve the academic performance of clinical medical students, enhance the sense of academic self-efficacy, and optimize diagnostic ability. The multi-teaching methods have high teaching satisfaction, which are worthy of further research and promotion by the education department.