Abstract: In this paper, the rapid and integrated manufacture method of 3D printing gun drill was put forward. The 3D printing process test of the composites gun drill composed of medium carbon steel drill shank, low alloy steel drill pipe and tungsten cobalt hard alloy drill bit was conducted. Microstructure and morphology of the composites gun drill interface between low alloy steel and medium carbon steel was analyzed using SEM. Phase composition and element distribution of the interface between low alloy steel and medium carbon steel were tested and analyzed by EDS and XRD. The defects, micro hardness and tensile strength of the interface between low alloy steel and medium carbon steel were tested and analyzed. The microstructure and properties of the interface of the composites were tested and analyzed, and the interface was characterized. The results show that the interface performance of 3D printing composites gun drill is better than that of the welding gun drill. The rapid and integrated 3D printing method is feasible for gun drill manufacture.