The invention belongs to the field of metal-based composite material additive manufacturing (3D printing), and particularly relates to a device and method for manufacturing metal-based composite materials through high flux. The device is composed of a machine body frame, a transmission system, a quantitative feeding system, a multi-nozzle on-demand spray deposition system and an initiation system.The device is of a rectangular rod type structure, a printing platform moves up and down in the Z-axis direction in the printing process, and the multi-nozzle on-demand spray deposition system movesalong the X-axis and the Y-axis; metal-based composite material suspension slurry with different components and contents is selectively and alternately sprayed through a plurality of nozzles layer bylayer, the suspension slurry is controlled to be solidified instantly, and preparation of the high-flux multi-component metal-based composite materials of gradient, laminated and hybrid structures isachieved. According to the method, the high-flux preparation thought and method are combined with the additive manufacturing technology so that a large number of multi-component, complex-appearance and special structure metal-based composite materials can be simultaneously and synchronously completed in a short time, and the material design, research and development and production cycle is shortened.