Superior collapse-prevention performance of the building structure can maintain its abundant integrity to realize the design target of collapse prevention at MCE(maximum considered earthquake) level. To investigate the seismic mechanism of innovative PEC column—steel beam composite frame with end-plate and pretension penetrating bolts connection, a 1/2 scale test specimen of inter-story substructure was designed and tested under lateral low-cycle reserved loading. Based on the test observation and measurements, the seismic performance including the failure process and failure mode, the hysteretic property, lateral stiffness degradation, energy dissipation capacity and drift deformation pattern were analyzed. Test results showed that the failure mode was primary induced by the plastic hinge of beam section adjacent to end plate; the displacement ductility coefficient and maximum equivalent viscous damping ratio of the specimen are 3.74 and 0.325 respectively, and the specimen own better seismic ductility and energy-dissipation capacity; the drift pattern as ideal inverted triangle pattern of flexure-shear type was formed due to its excellent integrity and lateral stiffness is evenly distributed along its height; the interstory drift ratio and connection rotations all surpassed the drift limit(1/30) of maximum consideration earthquake, correspondingly the specimen owned sound collapse prevention capacity
