A composite printing device featuring multi-spindle high-energy-particle-beam deposition welding and milling, comprising a machine base, a workbench, a multi-spindle milling device, the multi-spindle milling device including a milling base and a tool base; the workbench including an ejector base, the ejector base fitted with a welding gun. Through the guide of the first rail and second rail, the horizontal distance between the milling base and the workbench or the ejector base can be adjusted, so that the milling base can move to the upper side of the workbench or ejector base; and the milling clamp can hold the tool or welding gun to form a one-layer or multi-layer approximate shape on the workbench and to conduct profile milling, so as to obtain the right size and surface accuracy required for the mechanical part, removing the need for further processing.
