<p>Three full-scale specimen groups were meticulously designed and fabricated to investigate the positive bending moment behavior of orthotropic composite bridge decks suitable for self-anchored suspension bridges. The specimens were constructed using a steel deck plate and ultra-high-performance concrete (UHPC) layer, featuring a hybrid structural configuration to simulate real-world bridge loading conditions. The effects of different stud spacing and pre-stress on the ultimate bearing capacity, ductility, and failure mode of composite bridge deck were studied by four-point bending static loading. The results show that the cross-sectional deformation of the specimens during loading meets the assumption of a flat section and that this structure exhibits good ductility and loadbearing capacity. The main failure modes are U-rib yield and top crushing of the UHPC plate. The increase in bolt spacing increases the interlaminar slip of the specimen significantly, but has little influence on its flexural bearing capacity. Pre-stress application improves the specimens’ flexural bearing capacity and elastic range; however, it reduces the ultimate deflection of the specimens, affecting their ductility. Moreover, during loading, the internal-force increment of the pre-stressed tendons is relatively large, with the stiffness of the specimens and eccentricity of the pre-stressed tendons being the main influencing factors.</p>