Objective: To verify the volume similarity between unilateral mammary gland and autologous omentum in adult females. Methods: A total of 63 patients diagnosed with stage 0-II breast cancer and partial nonlactating multi-fistula mastitis in the breast surgery department of Inner Mongolia Xing'an League People's Hospital from 2007 to 2020 were enrolled in the study, including 52 cases of stage 0-II breast cancer and 11 cases of non-lactating multi-fistula mastitis. The volume of the resected mammary gland and the omentum were measured by a "soft tissue measuring cylinder" and recorded. The appearance of the reconstructed breast was compared with that of the healthy side. The correlation between unilateral mammary gland volume and autologous omentum volume was analyzed by linear regression. Results: Valid data were obtained for 60 cases. Affected breast size, curve, texture, nipple, and inframammary fold after omentum breast reconstruction were similar and symmetrical to those of the unaffected side. Postoperative complications occurred in most patients; the majority of these (76.67%) involved numbness of the nipple, and other complications were few. Patient satisfaction with postoperative appearance, feel, and movement of the breast, as well as total treatment costs, was over 75.0%. Linear regression analysis indicates a linear relationship between subcutaneous gland volume (x) and autologous omentum volume (y): y = 0.9847x -1.2132, R 2 = 0.9742. Conclusion: Only when the dissociated pedicled omentum is completely obtained under laparoscopy can the whole subcutaneous residual cavity of the mammary gland be filled to the same volume. This study verifies that the volume of the unilateral mammary gland is similar to that of the autologous omentum in adult females.