Objective: To investigate the effects of reducing blood transfusion in ventricular septal defect surgery on the volume of blood transfusion, safety and complications of children. Methods: A total of 72 children aged 4-10 years who underwent ventricular septal defect repair at Xinxiang Central Hospital between January 2018 and June 2019 were recruited in the study (38 males, 34 females). The patients were randomly divided into reduced transfusion group (36 cases) and control group (36 cases) in accordance with the random number table.Reduced transfusion group: (1) after anesthesia, 5 mL/kg of blood was drained from the central vein based on blood pressure and stored in a special citric acid anticoagulant blood storage bag which was then put into a 4 ℃refrigerator.(2) hemostasis was performed strictly from skin incision, and after sternum was sawed, the whole body was heparinized, wound bleeding was recovered, and autologous blood recovery device was used.(3) the extracorporeal circulation pipeline was shortened as far as possible, and in case of the intraoperative hematokrit (Hct) of above 0.18-0.20, no red blood cells were transfused.After stopping the extracorporeal circulation, the remaining blood from the membrane lung and pipeline was transfused back.(4) antifibrinolytic drugs were adequately used during operation, and autologous blood recovery device was used to salvage blood after protamine neutralization.(5) hemostatic drugs and hemostatic materials were used.(6) after admitted to intensive care unit (ICU) postoperatively, the blood pressure was controlled at an appropriate level, to avoid bleeding caused by high blood pressure.Blind rehydration should be also avoided, and unnecessary blood thinning should be reduced.(7) encouraging children to get out of bed early after surgery, so as to improve the gastrointestinal activity of children, thus enhancing nutrition.Control group: (1) unconventional preoperative preparation of autologous blood; (2) systemic heparinization before aortic intubation; (3) conventional extracorporeal circulation device; (4) routine treatment in ICU.Primary outcomes including general situation, the rate of erythrocytic transfusion, mean consumption of erythrocytes, intraoperative blood loss, the volume of postoperative drainage, operative time, ventilator weaning time, ICU stay time, hospital stay, hospitalization costs, the incidence of pulmonary infection, secondary endotracheal intubation rate, reoperation rate, intra-transportation colloid osmotic pressure (COP), as well as the intra-transportation, preoperative and postoperative concentration of hemoglobin (Hb) and Hct and those at discharge were compared. Results: All 72 patients rehabilitated and discharged from hospital successfully.The rate of erythrocytic transfusion in the reduced transfusion group and control group was 22.22% (8/36 cases) and 83.33% (30/36 cases), respectively, and the difference of which was statistically significant (χ²=93.12, P<0.05). The mean consumption of erythrocytes in the two groups were (1.56±0.68) U and (4.26±1.12) U, respectively, and the difference of which was statistically significant (t=1.18, P<0.05). Postoperative blood loss and drainage, hospital stay, and hospitalization costs in the reduced transfusion group were less than those in the control group (t=1.38, 2.35, 2.22, all P>0.05). There was no statistically significant differences in the operative time, ICU stay time, ventilator weaning time, the concentration of Hb and Hct at discharge between the two groups (t=0.25, 0.85, 0.85, 0.72, all P>0.05). In addition, there were also no differences in the incidence of pulmonary infection, secondary endotracheal intubation rate and reoperation rate between the two groups (χ²=56.36, 55.33, 55.33, all P>0.05). Conclusions Reducing intraoperative blood transfusion is safe and feasible for children with ventricular septal defect.Besides, it also helps reduce the volume of perioperative blood confusion, save hospitalization costs and reduce transfusion complications.