Abstract: A modified alloy powder includes a powdered alloy; and a carbide powder, mixed in the powdered alloy; wherein the carbide powder has a particle size smaller than that of the powdered alloy, and the carbide powder is dedicated to powder bed selective laser melting and laser metal deposition technology. Being used as a grain refiner and a grain growth inhibitor, the effect of refinement in the grain size of final products and improvement of the workpiece strength can be achieved.