Abstract:[Objective] To evaluate the value of 3D printing technology in open reduction and internal fixation (ORIF) of displaced ace- tabular fractures. [Methods] Clinical data of 32 patients with acetabular fracture admitted from January 2018 to June 2022 were retrospec- tively analyzed. According to the results of doctor-patient communication, 16 patients had ORIF performed by using 3D printing simulation preoperatively (3D group), while the 16 patients received traditional ORIF (traditional group). The perioperative, follow- up and imaging consequences were compared between the two groups. [Results] The 3D group proved significantly superior to the traditional group in terms of operation time [(203.4±47.2) min vs (248.2±72.1) min, P＜0.05], total incision length [(22.8±8.9) cm vs (31.3±12.9) cm, P＜0.05], fluoros- copy times [(7.3±1.8) vs (12.3±3.6) times, P＜0.05], intraoperative blood loss [(587.5±401.9) ml vs (885.0±417.7) ml, P＜0.05], blood transfu- sion volume [(132.8±154.4) ml vs (436.9±546.5) ml, P＜0.05] and ambulation time [(5.8±1.1) days vs (8.4±2.2) days, P＜0.05]. All patients in both groups were followed up for a mean of (23.5±10.1) months, and the 3D group resumed full weight-bearing activity significantly earlier than the traditional group [(89.1±3.8) days vs (94.6±4.9) days, P＜0.05]. The VAS scores, hip flexion-extension and internal-external rota- tion ROM, and Harris scores significantly improved over time in both groups (P＜0.05). The 3D group was significantly better than the tradi- tional group in terms of VAS score [1 month postoperatively, (3.5±1.5) vs (5.3±1.0), P＜0.05; 6 months postoperatively, (1.6±1.4) vs (3.4± 1.3), P＜0.05], Harris score [1 month after surgery, (56.4±5.3) vs (51.1±8.1), P＜0.05; 6 months after surgery, (78.1±5.1) vs (72.8±4.8), P＜ 0.05], nevertheless there were no significant differences between the two groups in hip flexion- extension and internal- external rotation ROM at any matching time points, and VAS and Harris scores at the latest follow-up (P＞0.05). Regarding to imaging, the 3D group was sig- nificantly better than the traditional group in fracture reduction quality (P＜0.05). Although there was no significant difference in fracture healing time between the two groups (P＞0.05), the 3D group was significantly superior to the traditional group in Tonnis grade for hip osteo- arthritis at the latest follow-up (P＜0.05), whereas with no femoral head necrosis in anyone in both groups. [Conclusion] 3D printing assist- ed ORIF of displaced acetabular fractures has the advantages of shortening operation time, decreasing trauma, reducing bleeding and X-ray radiation exposure, improving reduction quality and rapid recovery of hip function with fewer complications.