Objective:To construct an early warning model of postoperative lower limb lymphedema in patients with gynecological malignancies and evaluate it.Methods:A total of 565 patients with gynecological malignant tumors who underwent surgical treatment in our hospital were selected as the research objects.They were divided into modeling group (396 cases) and validation group (169 cases) according to 10:3,and then the modeling group was divided into edema group (78 cases) and non-edema group (318 cases) according to whether the patients had postoperative lower extremity lymphedema.Univariate analysis of the risk factors of lower extremity lymphedema in patients with gynecological malignant tumors was carried out,and multivariate Logisitic regression analysis was performed on the results of the univariate analysis to analyze the risk factors of lower extremity lymphedema in patients with gynecological malignant tumors.R (R4.0.1) and rms package was used to construct a nomogram early warning model for postoperative lower extremity lymphedema in patients with gynecological malignant tumors based on multivariate Logistic regression analysis results.Bootstrap repeated sampling method was used to draw Hosmer-Lemeshow calibration curve for model validation,P>0.05 indicates that the model accuracy was better.SPSS20.0 software was used to draw ROC curve to evaluate the discriminative degree of the model.Results:In this study,a total of 396 patients with gynecological malignant tumors were collected,of which 78 patients had lower limb lymphedema,accounting for 19.70%.Univariate analysis showed that postoperative radiotherapy,lymph node dissection,TNM staging,postoperative drainage time,and diabetes were the factors that affect the occurrence of postoperative lower limb lymphedema in patients with gynecological malignant tumors (P<0.05),but had nothing to do with factors such as body mass index,age,postoperative chemotherapy,living environment,and hypertension (P>0.05);further multivariate Logistic regression analysis was performed,and the results showed that postoperative radiotherapy,lymph node dissection,TNM staging,postoperative drainage time,and diabetes were independent risk factors affecting the occurrence of lower limb lymphedema in patients with gynecological malignant tumors after surgery (P<0.05).The area under the ROC curve of the modeling group was 0.817,and the sensitivity and specificity were 66.04% and 83.33%,respectively;the result of H-L test was χ²=3.215,P=0.278.The area under the ROC curve of the validation group was 0.773,the sensitivity was 66.35%,and the specificity was 84.62%;the result of H-L test was χ²=3.112,P=0.254,indicating that the early warning model had good accuracy and discrimination.Conclusion:Postoperative radiotherapy,lymph node dissection,TNM staging,postoperative drainage time,and diabetes are independent risk factors affecting postoperative lower limb lymphedema in patients with gynecological malignancies.The early warning model established by this has good discrimination and accuracy.It can help clinically identify people at higher risk and provide prevention and timely treatment.