The purpose of this study is to explore the effect of using 3D printed pelvic prosthesis to reconstruct bone defect after pelvic tumor resection. From June 2018 to October 2021, a total of 10 patients with pelvic tumors underwent pelvic tumor resection and 3D printed customized hemipelvic prosthesis reconstruction in our hospital. Enneking pelvic surgery subdivision method was used to determine the degree of tumor invasion and the site of prosthesis reconstruction. 2 cases in Zone I, 2 cases in Zone II, 3 cases in Zone I + II, 2 cases in Zone II + III and 1 case in Zone I + II + III. Patients had preoperative VAS scores of 6.5 ± 1.3, postoperative VAS scores of 2.2 ± 0.9, preoperative MSTS-93 scores of 9.4 ± 5.3 and postoperative 19.4 ± 5.9( < 0.05), all patients had improvement in pain after surgery; Postoperative complications included joint dislocation in 2 cases, myasthenia caused by Guillain-Barre syndrome in 1 case, delayed wound healing in 3 cases and wound infection in 2 cases. Postoperative wound-related complications and dislocations were associated with the extent of the tumor. Patients with tumor invasion of the iliopsoas and gluteus medius muscles had higher complication rates and worse postoperative MSTS scores ( < 0.05). The patients were followed up for 8 ∼ 28 months. During the follow-up period, 1 case recurred, 4 cases metastasized and 1 case died. All pelvic CTs reviewed 3-6 months after surgery showed good alignment between the 3D printed prosthesis and the bone contact, and tomography showed the growth of trabecular structures into the bone. Overall pain scores decreased and functional scores improved in patients after 3D printed prosthesis replacement for pelvic tumor resection. Long-term bone ingrowth could be seen on the prosthesis-bone contact surface with good stability.