Objective To observe the application effect of silicone prosthesis implantation combined with autologous fat granule transplantation in breast plastic surgery. Methods A total of 54 patients who underwent breast plastic surgery in our hospital from October 2020 to June 2022 were selected as the research objects. They were divided into control group and observation group by random number table method, with 27 cases in each group. The control group was implanted with silicone prosthesis, and the observation group was given autologous fat granule transplantation on the basis of the control group. The clinical operation indexes, chest uplift value, breast surgery result satisfaction and complications were compared between the two groups. Results The operation time of the observation group was longer than that of the control group (P <0.05). There was no significant difference in intraoperative blood loss and wound healing time between the two groups (P >0.05). The chest bulge value of the observation group was higher than that of the control group at 1, 3 and 6 months after operation (P <0.05). The satisfaction scores of breast size, relaxation state, breast symmetry and breast shape in the observation group were higher than those in the control group (P <0.05). The incidence of complications in the observation group was 7.41%, which was lower than 18.52% in the control group (P <0.05). Conclusion The application of silicone prosthesis implantation combined with autologous fat granule transplantation in breast plastic surgery is effective, which can improve breast shape, improve patients' satisfaction with breast plastic surgery, reduce chest uplift value, keep chest circumference relatively stable, and reduce the incidence of postoperative complications. It is worthy of clinical application.