As the core load-transferring component in long-span suspended structures, the reliability of sleeve connection joints in steel tie rods directly affects the overall structural safety. To investigate the influence of thread engagement depth and sleeve wall thickness ratio on joint bearing performance, this study conducted tensile tests on 12 full-scale specimens with different parameter combinations (6 groups for each parameter), analyzing typical failure modes and their evolution patterns under various configurations. A refined numerical analysis system considering threaded contact was established using ABAQUS finite element models. The results demonstrate significant parametric sensitivity in both load-bearing capacity and ductility characteristics. When thread engagement depth is less than 1.0d, uneven interfacial shear stress distribution leads to thread pull-out failure. However, when depth reaches 1.0d or more, the failure mode transitions to ductile necking fracture dominated by rod deformation, with maximum bearing capacity stabilizing. For sleeve wall thickness ratios below 0.225, brittle fracture occurs in sleeves due to stress concentration. When the ratio reaches 0.225 or higher, optimized stress distribution through enhanced sleeve stiffness shifts the failure mode to rod plastic deformation. Comparative analysis between theoretical models and experimental data validated critical condition equations for three failure modes, showing good consistency with error is within 4%. The study ultimately proposes a dual-control parameter design criterion: thread engagement depth should be ≥1.1d combined with sleeve wall thickness ratio ≥0.225, ensuring both high load-bearing capacity and controllable ductility for connection systems. This provides theoretical guidance for engineering applications.