A new hybrid connection system consisting of continuous waved tied bars and shear studs was developed for steel-concrete-steel (SCS) structures to achieve high-efficiency construction. Moreover, ultra-high-performance concrete (UHPC) was used in conjunction with the hybrid connection system to achieve steel-UHPC-steel (S-UHPC-S) structures with desirable resistance against intensity dynamic loads, such as impact and blast. To investigate the blast-resistant capacity of S-UHPC-S composite walls of a nuclear shell, four S-UHPC-S composite beams were extracted from the walls and tested under near-field blast with a cylindrical charge. In general, the S-UHPC-S composite beams showcased global response. For S-UHPC-S composite beams without web reinforcement, hairline flexural and horizontal cracks were observed under a scaled blast distance Z = 0.4 m/kg1/3. However, hairline shear cracks and horizontal cracks were formed once Z was decreased to 0.2 m/kg1/3. Installing waved tied bars can effectively mitigate the development of shear cracks. Decreasing longitudinal reinforcement ratio was prone to changing the failure mode from shear failure to flexure failure.