Abstract: Objective To evaluate the clinical efficacy and safety of hysteroscopy endo-operative system （HEOS） cold knife hysteroscopic micro-shear separation in the clinical treatment of patients with intrauterine adhesion. Methods 200 patients with intrauterine adhesion were enrolled and divided into the observation （n = 100） and control groups （n = 100） according to different treatment methods. In the control group, patients were treated with traditional hysteroscopic electrosurgical separation, and those in the observation group received HEOS cold knife hysteroscopic micro-shear separation. The surgical indexes, clinical efficacy and postoperative complications were statistically compared between two groups. Results In the observation group, the operation time was significantly shorter, and the amount of intraoperative bleeding and absorption of uterine distention fluid were significantly less than those in the control group （all P < 0.05）. There was a significant difference in clinical efficacy between two groups （P < 0.05）. In the observation group, the cure rate was 61%, higher than 45% in the control group （P < 0.05）. In the observation group, postoperative bleeding occurred in 1 case, 2 cases of infection and 1 case of pelvic adhesion. The incidence of postoperative complications was 4%. In the control group, postoperative bleeding occurred in 5 cases, 2 cases of infection, 3 cases of ectopic pregnancy and 5 cases of pelvic adhesion. The incidence of postoperative complications was 15%, which was significantly higher than 4% in the observation group （P <0.05）. Conclusion HEOS cold knife hysteroscopic micro-shear separation is an efficacious and safe treatment for patients with intrauterine adhesion.