Objective To analyze the effect of biplane silicone gel prosthesis implantation simultaneously combined with autologous fat transplantation composite breast augmentation in patients with mammaplasty. Methods From July 2022 to July 2023, 50 patients with mammaplasty in Nanjing Star-studded Health Cosmetic Hospital were selected as the research subjects. According to the different operative methods, they were divided into control group and observation group, with 25 patients in each group. The control group was treated with silicone gel prosthesis implantation augmentation, and the observation group was treated with biplane silicone gel prosthesis implantation simultaneously combined with autologous fat transplantation composite breast augmentation. The fat survival rate, mammaplasty effect and complication rate were compared between the two groups. Results After 6 and 12 months of operation, the fat survival rate in the observation group was higher than that in the control group (P<0.05). After 6 and 12 months of operation, the scores of breast aesthetics, breast touch and patient satisfaction in the observation group were higher than those in the control group (P <0.05). The incidence of complications in the observation group was 0, which was lower than 16.00% in the control group (P <0.05). Conclusion The application of biplane silicone gel prosthesis implantation simultaneously combined with autologous fat transplantation composite breast augmentation in patients with mammaplasty is effective, which can effectively improve the fat survival rate and the mammaplasty effect, with good recovery of breast aesthetics and tactile sensation. Moreover, the patient satisfaction is higher, and the incidence of postoperative complications is lower, so the safety is higher.