Objective To investigate the effects of rectus abdominis area （RAA）， visceral fat area （VFA）， and the ratio of visceral to subcutaneous fat area （V/S ratio） on the risk of surgical site infection （SSI） following open radical surgery for hepatocellular carcinoma （HCC） and their predictive value in the perioperative period and potential utility for intervention. Methods In this retrospective case-control study， 280 patients who underwent open radical HCC surgery between December 2019 and October 2024 were included. After excluding 17 patients due to incomplete data or other exclusion criteria， the remaining 263 patients were categorized into two groups： 66 in the SSI group and 197 in the non-SSI group. VFA， subcutaneous fat area （SFA）， and RAA were quantified using preoperative abdominal computed tomography （CT） scans. Propensity score matching was performed to create two well-balanced cohorts， each consisting of 59 patients. Multivariate logistic regression analysis and receiver operating characteristic （ROC） curve analysis were conducted to identify and evaluate potential risk factors for SSIs. Additionally， a nomogram was developed to assess the predictive performance of these risk factors through ROC curve analysis， calibration plots， and decision curve analysis. Results Preoperative laboratory results revealed significantly elevated white blood cell counts， C-reactive protein levels， and procalcitonin in the SSI group， along with reduced hemoglobin and serum albumin levels compared to the control group （P = 0.003）. Imaging analyses demonstrated markedly increased RAA （P = 0.032）， VFA （P = 0.015）， and V/S ratio （P = 0.002） in the SSI group. Univariate and multivariate logistic regression analyses identified RAA， VFA， and the V/S ratio as critical risk factors for SSIs. ROC curve analyses further confirmed the robust predictive capacity of the V/S ratio （AUC = 0.88） and RAA （AUC = 0.79）. A nomogram constructed based on these indicators achieved an AUC of 0.836， indicating excellent discrimination ability， strong concordance between predicted and observed outcomes， and clinically significant net benefit across a range of common threshold probabilities. Conclusions RAA， VFA， and the V/S ratio are critical predictors of SSI following open radical HCC surgery. The nomogram constructed based on these factors exhibits robust discrimination， calibration， and clinical utility， allowing clinicians to accurately identify high-risk patients and implement targeted interventions to reduce SSI incidence and enhance patient outcomes.