To expand the breeding space of rigid frame cages, a new type of combined rigid frame cage with a hinged outer cage on the base of the rigid frame cage was put forward. The hydrodynamic performance of the model was analyzed by using the marine engineering hydrodynamic software OrcaFlex. Under the conditions of pure flow, pure wave, and wave-current, the effective tension of the connection point between the floating frame and the net clothing of the combined rigid frame cage and the hinged rigid frame cage, the residual volume of the cage and the anchor rope force were compared and analyzed. At the same time, the Kinematic response of the hinged system of the combined rigid frame cage was analyzed. The results show that: compared with the rigid frame cage, the force of the connection point between the floating frame and the net clothing and the anchor rope is increased; the hinged outer cage can expand the breeding space and does not affect the remaining volume of the inner cage. The purpose of expanding the breeding space can be achieved by articulating the outer cage based on the steel frame cage, and the research results can provide a reference for the application of the hinged outer cage in practice to expand the breeding space.