Objective To improve the traditional case-based learning model and explore the effectiveness of a new teaching model in the instruction of Military Hygiene.

Methods A four-in-one new teaching model was applied in the teaching of the Environmental Hygiene section of Military Hygiene, integrating case-based learning with teaching cases spanning the section, lecture-based learning, team-based learning, and problem-based learning, highlighting a comprehensive focus on guided interaction in classroom, basic knowledge instruction, student engagement, and instructional content supplementation. This new teaching model was applied in Grade 2019 Class 1 and Grade 2020 Class 2 of the five-year clinical medicine program, while the traditional teaching model was used for Grade 2018, Grade 2019 Class 2, and Grade 2020 Class 1 of the five-year clinical medicine program. The effectiveness of the two models was compared according to the result of course examinations.

Results Compared with the traditional model, the new teaching model significantly improved students' scores in some subjective questions (Grade 2019: 16.2 vs. 13.2 (Control), P < 0.001; Grade 2020: 15.2 vs. 14.2 (Control), P=0.002). However, it had little impact on objective questions and some short-answer questions examining the memory of knowledge (Grade 2019, objective questions: 10.6 vs. 10.7 (Control), P=0.925; Grade 2020, the accuracy rate of 2^nd short-answer questions: 18.9% vs. 22.5% (Control), P=0.600), even reducing the accuracy rate for such questions (Grade 2020, 2^nd noun explanation: 0.6 vs. 1.0 (Control), P=0.012).

Conclusion The "four-in-one" new teaching model can enhance students' knowledge understanding and comprehensive abilities, which is suitable for the teaching of the Environmental Hygiene section of Military Hygiene that features fewer class hours and scattered content. However, the new teaching model can hardly strengthen the memory of basic knowledge, which needs further improvement.