To investigate the clinical effect of total hip replacement (THA) in the treatment of traumatic arthritis secondary to acetabular fracture. From October 2019 to June 2022, 15 patients with secondary traumatic arthritis of acetabulum fracture were treated with THA. There were 8 males and 7 females, aged from 40 to 76 years old with an average of (59.20±9.46) years old. Prosthesis loosening, dislocation of hip joint, range of motion of hip joint, nerve injury and other conditions were recorded before and after surgery. Harris score, visual analogue scale (VAS) and imaging were used to evaluate hip joint function and surgical effect. Follow-up time ranged 6 to 39 months with an average of (18.33±9.27) months. All the 15 patients successfully completed the operation, no nerve and blood vessel injury during the operation, postoperative wound healing was stageⅠ, no infection, one case of acetabular side prosthesis loosening at half a year after operation, and recovered well after revision surgery, one case of hip dislocation was cured after open reduction treatment, no adverse consequences. Harris score at the last postoperative follow-up was (88.60±4.01) points, compared with the preoperative (47.20±11.77) points, the difference was statistically significant (P<0.05), and VAS at the lateat postoperative follow-up was 1 (1) points, compared with the preoperative 8 (2) points, the difference was statistically significant (P<0.05). At the last follow-up, the pain symptoms were relieved or disappeared, and the joint function was satisfactory. The imaging data of the latest follow-up showed joint was well pseudoradiated, no abnormal ossification occurred, and the prosthesis was not loose. THA is effective in the treatment of traumatic arthritis secondary to acetabular fracture and can effectively improve the quality of life of patients. Preoperative comprehensive evaluation and bone defect evaluation of patients, and intraoperative management of acetabulum, femur, internal fixation and bone defect are key factors for the success of surgery.