The utility model provides a combined device of a plate blank continuous casting crystallizer for submersed nozzle defection flow injection, comprising a crystallizer, a nozzle and a flow-injecting port. The combined device is characterized in that two holes on the lateral surface of the nozzle are used for injecting flow, the flow injection-port horizontally or downwards tilts and the nozzle is arranged in the crystallizer along the horizontal deflection direction. In the utility model, two holes are used for injecting flow, the flow-injecting port downwards tilts, the nozzle is arranged along horizontal deflection direction, four corners of the crystallizer wall are right angles or round angles and the nozzle of the crystallizer deflects for injecting flow, so molten steel in the crystallizer rotatably flows, the fluctuation range of the level is reduced, the temperature of the molten steel is balanced and inclusion in the steel is rotatably centralized in the center of the crystallizer; in addition, the time of liquid phase is prolonged, which is beneficial to upward-floating of the inclusion and can effectively improve the purity of the molten steel.