In patients with Crowe III developmental dysplasia of the hip (DDH), surgery presents challenges such as severe bone defects and inadequate acetabular cup coverage. This study compares the clinical efficacy of 3D-printed personalized Augments prostheses with conventional femoral head reshaping and structural bone grafting in total hip arthroplasty (THA) for patients with Crowe III DDH. A retrospective analysis was conducted on 52 Crowe III patients. The 3D group (26 cases) used 3D printing technology combined with computer simulation to design personalized Augments prostheses. Preoperative models were printed to simulate the surgical procedure, and high-porosity porous structured Augments prostheses and acetabular cup layers were printed using titanium alloy powder. The non-3D group (26 cases) underwent traditional femoral head reshaping and structural bone grafting. The study compared the differences in lower limb length, the horizontal and vertical distances of the hip joint rotation center from the teardrop line, acetabular cup abduction angle, acetabular cup coverage, operation time, intraoperative blood loss, postoperative time to mobilization, time to hospital discharge, Harris hip scores during follow-up, and complications between the two groups. In the 3D group compared to the non-3D group, intraoperative blood loss (261.92 ± 14.70 vs. 313.85 ± 20.02 ml, P < 0.05), time to mobilization (1.27 ± 0.45 vs. 4.85 ± 1.05 days, P < 0.05), and time to discharge (2.77 ± 0.65 vs. 5.85 ± 0.92 days, P < 0.05) were significantly lower, as was the limb length discrepancy on the first postoperative day (0.25 ± 0.21 cm vs. 0.48 ± 0.28 cm, P < 0.05). The acetabular cup coverage rates on the first postoperative day and at 3 months postoperatively (1 ± 0.00 vs. 0.93 ± 0.07; 1 ± 0.00 vs. 0.83 ± 0.11, P < 0.05) were significantly higher in the 3D group. The Harris hip scores at 3, 6, and 12 months postoperatively were also higher in the 3D group than in the non-3D group, with statistically significant differences (P < 0.05). The application of 3D-printed personalized augment prostheses in total hip arthroplasty provides a relatively feasible treatment option for patients with Crowe type III DDH. This approach contributes to personalized treatment and shows potential in improving surgical accuracy and certain treatment outcomes.