Objective:To analyze the causes and influencing factors of conversion from laparoscopic surgery to laparotomy.Methods:To analyze and summarize the clinical data of 84 patients who converted to laparotomy in 16 203 cases of laparoscopic surgery from August 2017 to August 2020 in the Department of Gynecology of the Affiliated Hospital of Qingdao University, each patient converted to surgery was matched with 2 patients who underwent simple laparoscopic surgery. The patients were divided into conversion to laparotomy group (84 cases) and control group (168) cases, and analyze the influencing factors of laparoscopic conversion to laparotomy. χ 2 test or corrected χ 2 test or Fisher exact probability method were used for the comparison of counting data between groups, and conditional regression analysis was used for the multivariate analysis of case control design. Results:The conversion rate of gynecologic laparoscopic surgery to laparotomy was 0.52%(84/16 203). The reasons for 84 cases of conversion from laparoscopic surgery to open surgery were as follows: pelvic adhesion 50.0%(42/84), unexpected malignant tumor 19.0%(16/84), tumor oversize or special shape and location 14.3%(12/84), hemostasis difficulty 7.1%(6/84), multiple uterine fibroids 3.5%(3/84), simultaneous surgery 3.5%(3/84), bladder injury 1.2%(1/84), and subcutaneous emphysema 1.2%(1/84) during the operation. There were no significant differences in body mass index and comorbidities (diabetes, hypertension, coronary heart disease, thyroid disease) between the two groups (all P>0.05). And the history of endometriosis was 36.9% (31/84) and the history of pelvic surgery in the transperitoneal group was 60.7% (51/84) higher than that in the conversion to laparotomy group of 20.8% (35/84), 30.6% (51/84) (χ 2=7.482, 21.42, P=0.006). The results of conditional regression analysis showed that that surgical history( OR=3.979, 95% CI 2.010-7.874, P<0.001 and thyroid history ( OR=15.333, 95% CI 1.087-216.346, P=0.005) increased the risk of conversion to laparotomy; Hypertension history ( OR=0.203, 95% CI 0.067-0.622, P=0.005) reduced the risk of conversion to laparotomy. Further analysis of which operation type affected the conversion to laparotomy showed that cesarean section ( OR=2.105, 95% CI 1.109-4.351, P=0.044), myomectomy ( OR=11.605, 95% CI 3.306-40.735, P<0.001), and ovarian cyst removal ( OR=7.914, 95% CI 2.157-21.037, P=0.002) affected the conversion to laparotomy. Conclusion:The main reason for conversion from gynecologic laparoscopic surgery to laparotomy is pelvic adhesion. The history of surgery and thyroid disease are the risk factors for conversion to laparotomy. Among them, myomectomy and ovarian cyst removal are important factors for conversion to laparotomy. Before operation, appropriate clinical operation methods should be selected according to the patient's medical history and condition to ensure the patient's safety.