Objective <p>To compare the clinical outcomes of open reduction and internal fixation (ORIF) versus percutaneous multiple-trajectory screw fixation (PMSF) in the treatment of unstable pelvic fractures with severe polytrauma, and to provide a basis for optimizing surgical strategies.</p> Methods <p>A prospective study included 26 patients (January-July 2024) divided into ORIF (<i>n</i> = 15) and PMSF (<i>n</i> = 11) groups. ORIF used traditional open plating/screws, while PMSF employed fluoroscopy-guided minimally invasive screws. Primary outcomes: operative time, blood loss, complications (infection, nerve injury), fracture reduction (Matta criteria), functional recovery (Majeed score). Secondary outcomes: hospital stay, preoperative waiting time. Age, ISS, and Tile classification were controlled. SPSS 27.0 analyzed data (significance <i>P</i> &lt; 0.05).</p> Results <p>The PMSF group demonstrated significantly shorter preoperative waiting times (124.09 ± 54.45&#xa0;h vs. 260.67 ± 170.92&#xa0;h, <i>P</i> = 0.018), less intraoperative blood loss (68.18 ± 49.96 mL vs. 510.00 ± 264.71 mL, <i>P</i> &lt; 0.001), and shorter hospital stays (23.36 ± 8.64 days vs. 33.93 ± 12.54 days, <i>P</i> = 0.024) compared with the ORIF group. There were no significant differences in the rates of excellent/good fracture reduction (Matta criteria: PMSF 90.91% vs. ORIF 86.67%, <i>P</i> = 1.000) or 12-month Majeed scores (82.73 ± 7.89 vs. 75.40 ± 13.64, <i>P</i> = 0.125) between the two groups.</p> Conclusion <p>For patients with unstable pelvic fractures with severe polytrauma, PMSF offers a better minimally invasive treatment option over traditional ORIF in terms of reducing trauma and shortening rehabilitation periods, while achieving comparable fracture reduction quality and functional recovery. Therefore, PMSF can be considered a preferred choice for such cases.</p> Trial registration <p>This study was retrospectively registered. Chinese Clinical Trial Registry (ChiCTR2500110578; Registration date: 16/10/2025;PID:288327).</p>