The invention discloses a device and a method for the use of an impeller of a laser 3D (three dimensional) -printing pump, and belongs to the field of 3D printing technology. The device comprises a laser system, a gas protection system, a preheating system, a powder feeding system, a powder paving system, a powder recycle system and a computer system. The manufacturing method mainly comprises the following steps that 1, a CAD solid model of the pump impeller is drawn, and the model is subjected to hierarchical slicing along the Z direction; 2, the slice in each layer is zoned into a zone I and a zone II according to the performance requirements of the pump impeller; 3, the zone I of each slice layer is subjected to low-speed sintering by using powder A, and the zone II is subjected to low-speed sintering by using powder B. The surface of a workpiece and the powder flow filed are subjected to the inert gas shielding in the process of printing. According to the device and the method for the use of the impeller of the laser 3D-printing pump, different requirements of different positions of the pump impeller on mechanical performance can be met, the printing quality and speed are also improved, and the manufacturing cost is reduced.