Objective:To explore the relationship between perioperative heparin dose and postoperative bleeding.Methods:From January 2000 to October 2022, we searched PubMed, EMbase, Cochrane Library, CNKI, CBM, WanFang Data and other databases by computer. This study explored the literature of controlled clinical trials on the correlation between heparin dosage and postoperative bleeding, and used Review Manager 5.4 software for statistical analysis.Results:A total of 10 studies with a total of 829 patients were included in this study. The results of meta-analysis showed that postoperative blood loss in high-dose heparin patients was significant, and the difference was statistically significant between high-dose and low-dose groups( MD=108.4, 95% CI: 85.55-131.33, I2=0, P<0.0001). The proportion of blood transfusion was also significantly increased in the high-dose group( OR=2.32, 95% CI: 1.10-4.89, I2=62%, P=0.03). However, there was no effect on postoperative death at 30 days and ICU stay time. Conclusion:High dose heparin significantly increases postoperative blood loss and the proportion of postoperative transfusions required, but has no significant effect on postoperative death at 30 days and ICU stay time.