Objective To investigate the clinical effect of endoscopy-assisted modified radical mastectomy combined with prosthesis implantation in patients with early-stage breast cancer. Methods A total of 160 patients with early breast cancer admitted to our hospital from June 2018 to June 2022 were selected as the research objects. According to different treatment methods, they were divided into control group (n =71) and observation group (n =89). The control group received endoscopyassisted modified radical mastectomy, and the observation group received endoscopy-assisted modified radical mastectomy combined with prosthesis implantation. The perioperative indexes, hospitalization time and hospitalization expenses, excellent and good rate of breast cosmetic effect, quality of life, self-esteem level, satisfaction and psychosocial adaptation level were compared between the two groups. Results There was no significant difference in intraoperative blood loss, operation time, drainage tube removal time and total drainage volume of 3 days between the two groups (P >0.05). The hospitalization time of the observation group was longer than that of the control group, but the difference was not statistically significant (P >0.05), while the hospitalization cost of the observation group was higher than that of the control group (P <0.05). The excellent and good rate of breast cosmetic effect in the observation group was higher than that in the control group (P <0.05). The scores of SF-36, RSES, CSQ-8 and PAQ in the observation group were higher than those in the control group (P <0.05). Conclusion The effect of endoscopy-assisted modified radical mastectomy combined with prosthesis implantation in patients with early-stage breast cancer is accurate, which can optimize relevant clinical indicators, speed up recovery, improve breast cosmetic results, improve quality of life and patient satisfaction. It is worthy of application.