The COVID-19 outbreak has created turbulence and uncertainty into multiple aspects of life in countries around the world. In China, the pandemic continues to pose a great challenge to the nature of traditional in-class education in schools. Chinese education has faced the difficult decision of whether to resume in-person teaching in an unprecedented and time-pressured manner.To ensure the quality of teaching and learning during this time, this study aims to explore the effectiveness of an "online + in-person" hybrid teaching model with a new three-part approach to the hybrid teaching lab, where students prepare for the in-person lab using virtual simulated experiments and learning modules and debrief their learning afterwards online as well. This approach not only enhances the efficiency during the in-person lab but also strongly reinforces concepts and laboratory skills by providing a "practice run" before physically attending the lab. A total of 400 medical undergraduates from Dalian Medical University in China were recruited for this study. In an undergraduate molecular biology laboratory course, we observed 200 students in a hybrid teaching model. We evaluated the learning outcomes from the "online + inperson" hybrid teaching model with a questionnaire survey and assessed the quality of experiment execution, report writing, and group collaboration. Moreover, the 200 students from the hybrid group were evaluated during an annual science competition at the university and compared to 200 students from the competition cohort who had no experience with a hybrid learning model. The comparison data were analyzed using a student's t-test statistical analysis. The students in the hybrid learning group demonstrated a strong enthusiasm for the model, high amount of time utilizing the online system, and high scores on laboratory evaluation assignments. Approximately 98% of the hybrid learning students reported that they preferred mixed teaching to the traditional teaching mode, and all students scored above 96% on the online laboratory report.Teachers of the course observed that the hybrid group had a noticeably higher level of proficiency in lab skills compared to the previous students. At the Abbreviations: ICC, immunocytochemistry; q-PCR, quantitative real time polymerase chain reaction.Zheng Sun and Zihan Xu contributed equally to this work.