This study retrospectively analyzed the clinical data of a 47-year-old woman with a giant presacral teratoma complicated by chronic infection and multiple cutaneous sinus tracts, to evaluate the feasibility and safety of transsacrococcygeal resection combined with single-stage pelvic floor reconstruction using a biologic mesh. Following a preoperative multidisciplinary discussion to assess the surgical approach, the tumor and associated infected sinus tracts were resected en bloc via a transsacrococcygeal approach. During the same operation, pelvic floor reconstruction was performed using a porcine small intestinal submucosa (SIS) biologic mesh to wrap and support the bulging posterior rectal wall. The tumor was completely excised, and histopathological examination confirmed a mature teratoma. The incision healed by primary intention, with no seroma, mesh infection, or delayed wound healing. At the 6-month postoperative follow-up, no recurrent infection or perineal hernia was observed, and the Wexner constipation score was 1. This case suggests that, in selected patients with giant presacral teratomas complicated by chronic infection and cutaneous sinus tracts, the transsacrococcygeal approach may enable complete tumor resection and infection control, while single-stage pelvic floor reconstruction using an SIS biologic mesh may be feasible and safe in the short term.