This study investigates the influence of span-to-shear ratios on the stability and reliability of prefabricated high-strength steel-concrete structures under seismic action, focusing on through bolts as critical connectors. Three prefabricated high-strength steel-concrete structure specimens with span-to-shear ratios of 1.0, 2.0, and 3.0 were fabricated and subjected to cyclic loading simulating earthquakes. Vulnerability, strength degradation, stiffness degradation, and energy dissipation capacities of the specimens under cyclic loading were evaluated. Results indicate specimens with span-to-shear ratios of 2.0 and 3.0 exhibit high vulnerability at through bolts, manifesting considerable damage and causing wide concrete cracks. By contrast, specimens with a 1.0 ratio demonstrate substantially reduced vulnerability at through bolts, enhanced structural stiffness, and excellent energy dissipation capacity, resulting in narrow crack widths and improved crack resistance. Thus, prefabricated high-strength steel-concrete structures with a span-to-shear ratio of 1.0 exhibit optimal seismic stability and reliability, particularly at through bolt locations. These findings offer critical insights for the optimized design and engineering applications of these structural systems in seismic environments.