Nutritional therapy is an important component of comprehensive clinical diagnosis and treatment. Strengthening clinical nutrition education can help resident physicians improve their level of nutrition diagnosis and treatment. This study introduced a hybrid teaching method that combines online and offline teaching into the teaching of clinical nutrition for 437 resident physicians, and observed its application effect. For all resident physicians in our hospital in 2023, the basic knowledge classroom of clinical nutrition was set up through online teaching, and combined with offline case-based clinical nutrition diagnosis and treatment teaching classroom as an example, the teaching design and implementation process of blended learning in resident physician clinical nutrition teaching were elaborated. The basic knowledge mastery of resident physicians was compared before and after training through knowledge test. The effectiveness of teaching was evaluated by comparing indicators such as nutritional risk screening rate and 24-hour nutritional risk screening rate to understand the nutritional diagnosis and treatment of resident physicians before and after training. The results showed among the 437 resident physicians who participated in the training, the qualification rate of clinical nutrition basic knowledge significantly improved after training from 18.8% (82/437) to 100.0% (437/437). The nutritional risk screening rate of hospitalized patients increased from 30.5% (9 181/30 103) to 91.3% (28 329/31 029), and the nutritional risk screening rate within 24 hours increased from 20.1% (6 051/30 103) to 36.8% (11 419/31 029). The qualified rate of nutritional risk screening increased from 51.2% (4 475/8 740) to 84.9% (7 420/8 740). The evaluation rate increased from 3.2% (968/30 103) to 9.9% (3 072/31 029), and all differences were statistically significant (all P<0.001).The questionnaire survey results showed that the satisfaction rating of resident physicians with blended learning was (4.85±0.36) points, and the satisfaction rating of blended learning in improving clinical nutrition diagnosis and treatment level was (4.82±0.39) points. It can be seen that the application of blended learning in the clinical nutrition teaching of resident physicians helps them to master clinical nutrition knowledge and improve their practical abilities of clinical nutrition diagnosis and treatment.