Objective To explore the application effect of scene simulation teaching mode based on 3-class in nursing teaching of cardiopulmonary bypass in cardiovascular surgery. Methods A total of 60 nursing students who practiced in cardiovascular surgery in Department of Cardiovascular Surgery of Chongqing Hospital of Chinese Academy of Sciences from October 2019 to September 2021 were selected as the research objects. They were divided into two groups according to the practice time, 30 nursing students who practiced from October 2019 to September 2020 were set as the control group，using the traditional nursing teaching method, 30 nursing students who joined the practice from October 2020 to September 2021 were set as the intervention group, and on the basis of the control group, the scene simulation teaching mode based on 3-class was used. The scores of core competence (CINS), problem solving ability (PSI) and cardiopulmonary bypass nursing technology of the two groups of nursing students before and after practice were compared. Results There were no significant differences in the scores of CINS and PSI between the two groups (P>0.05) .The scores of CINS and PSI of nursing students in the intervention group were higher than those in the control group,and the assessment results of cardiopulmonary bypass nursing technology were higher than those in the control group,the differences were statistically significant (P<0.05). Conclusions The scene simulation teaching mode based on 3-class can improve the core ability, problem-solving ability and cardiopulmonary bypass nursing technology practice ability of cardiovascular surgery nursing students, which is worthy of clinical application.