Background: The pelvis contains abundant trabecular bone, and conventional percutaneous sacroiliac lag screws may exhibit fixation failure when used to repair sacroiliac joint injuries in patients with osteoporosis. The development of a screw that can effectively hold trabecular bone has significant clinical implications. Objective: To investigate the biomechanical performance of a newly developed sacroiliac lag screw. Methods: A commonly used percutaneous sacroiliac lag screw was used as a control. Polyurethane material was used to simulate trabecular bone, and the pullout resistance of the Novel Sacroiliac Spiral Blade Screw was tested using an Instron mechanical testing machine. Pelvic specimens were used to analyze the mechanical effects of the Novel Sacroiliac Spiral Blade Screw in repairing sacroiliac joint injuries under normal standing conditions. Static stiffness and dynamic stability were measured, with the normal pelvis, percutaneous sacroiliac lag screw - single screw repair, and percutaneous sacroiliac lag screw - double screw repair as controls. Results: The damage to the polyurethane material after screw extraction was less pronounced in the Novel Screw group. The average effective holding displacement for the Novel Screw was approximately (8.81±0.21) mm, significantly greater than the average displacement of the percutaneous sacroiliac lag screw (0.60±0.02) mm. However, the maximum resistance to pullout for the percutaneous sacroiliac lag screw was significantly higher than that for the Novel Screw. The stiffness after repair of sacroiliac joint injuries was significantly higher when using a single Novel Screw compared to using two percutaneous sacroiliac lag screws. The displacement amplitude was highest in the sacroiliac joint injury group, with a value of (0.995±0.021) mm. The normal group had the second highest displacement amplitude, with a value of (0.520±0.011) mm. The displacement amplitudes in the other groups were similar but significantly different with P-values less than 0.05. The dynamic stability was the best in the novel screw repair group, slightly better than the percutaneous sacroiliac lag screw - double screw repair group, and the worst in the sacroiliac joint injury group. The novel sacroiliac lag screw effectively repaired sacroiliac joint injuries. Conclusion: The novel sacroiliac lag screw can effectively hold trabecular bone and has practical clinical utility.