Objective:To explore the application effect of "sandwich" teaching in the standardized residency training of blood purification center.Methods:A total of 72 residents who participated the standardized residency training of blood purification center of The Third Hospital of Mianyang from July 2019 to November 2019 and December 2019 to April 2020 were selected to be divided into control group and research group in average. The control group used traditional teaching and the research group took "sandwich" teaching, respectively. The two groups of subject assessment results and post competency before and after the teaching were compared. SPSS 23.0 software was used for t test and chi square test. Results:The research group's academic knowledge test scores and practical operation skills test scores were (91.64±5.38) points and (86.81±5.30) points respectively, and those in the control group were (84.25±5.26) points and (78.28±5.07) points respectively, and the scores in the study group were higher than those in the control group ( P<0.05). After teaching, the assessment scores of personal quality, professional knowledge, professional skills, professional ability and self-concept of the research group were (18.61±2.38) points, (18.28±2.29) points, (17.56±2.20) points, (18.81±2.41) points and (17.75±2.34) points respectively, and those in the control group were (16.42±2.19) points, (15.81±2.37) points, (15.06±2.41) points, (16.31±2.35) points and (15.31±2.28) points respectively. All above scores of the two groups after teaching were higher than those before teaching ( P<0.05), and those of the research group after teaching were higher than those of the control group ( P<0.05). Conclusion:"Sandwich" teaching can improve the examination results and post competency of the residents during the standardized residency training of the blood purification center.