Objective To explore the application effects of blended learning inbasic life support training for retraining trainees. Methods An experimental control method was used. A total of522 retraining trainees from East Hospital Affiliated to Tongji University who participated in the basic life support training were selected as the subjects, all of whom were hospital physicians. 265 retraining trainees who participated in the training from March to April 2023 were set as the experimental group, using blended learning mode; and 257 retraining trainees who participated in the training from March to April 2021 were set as the control groupusing blended learning mode. The teaching effectiveness were evaluated through the skill assessments of two groups of trainees and a questionnaire survey of trainees participating in blended learning mode. χ²-test and t-test were used for data analysis. Results The first-time pass rate of skill assessment among the experimental group trainees was higher than that of the control group trainees [90.6% (240/265) vs. 84.4% (217/257)](P=0.034). The survey results showed that the average score of the experimental group's liking for using blended learning mode for retraining was (4.73±0.64) points, and the average score of confidence in using basic life support in practice after receiving the course was (4.78±0.62) points. In addition, 96.6% (256/265) of the experimental group believed that adopting a blended teaching mode would facilitate more flexible learning, while 95.5% (253/265) believed that it would help to systematically master basic life support knowledge and skills. Conclusions The blended learning mode helps to improve the retraining trainees' pass rate of skills assessments in the training of basic life support. It has the advantage of allowing students to learn more flexibly and systematically to master knowledge and skills, and to enhances their confidence in using basic life support skills.