Robot-assisted natural orifice specimen extraction surgery (NOSES) for sigmoid colon cancer represents an innovative, minimally invasive surgical technique that integrates the benefits of minimally invasive surgery with natural orifice specimen extraction. In this study, a 67-year-old male patient diagnosed with sigmoid colon cancer underwent Kangduo surgical robot-assisted NOSES, with a total operative time of 290 min and an estimated intraoperative blood loss of 50 mL. The procedure involved robotic-assisted radical resection of the sigmoid colon, regional lymphadenectomy, and specimen extraction through a natural orifice. Postoperative histopathological analysis confirmed the absence of residual malignancy in the resected sigmoid colon, while 12 pericolic lymph nodes exhibited reactive hyperplasia. Both the proximal and distal surgical margins were negative for malignancy. The patient had an uneventful recovery and was discharged on postoperative day 7. The precision and flexibility of the robotic system facilitated NOSES by minimizing abdominal wall trauma, reducing postoperative complications, and shortening recovery time. This finding indicates that robot-assisted NOSES is a safe and feasible approach for the surgical treatment of sigmoid colon cancer, though further clinical experience and long-term follow-up are required to comprehensively assess its efficacy.