The invention relates to a 3D printer for metal powder and belongs to the field of 3D printing equipment. According to the 3D printer for the metal powder, the structural design is reasonable, operation is convenient, the powder laying quality is good, the powder is preheated uniformly, the part machining time is greatly shortened, formed parts are taken easily and conveniently, automatic powder adding operation can be achieved, a large quantity of manpower and material resources are saved, and an operator is prevented from inhaling a large amount of the powder. According to the adopted technical scheme, a first electric push rod is mounted on the inner side of a powder outlet sleeve, a lifting device is mounted on the inner sides of a connecting plate and a positioning plate, a conical hole, a shielding plate, a jacking rod and a guiding pipe connected with the conical hole are arranged on a lifting plate to suck the powder around the parts, an electric heating pipe is arranged on theinner side of the upper end of the powder outlet sleeve to preheat the powder, an anti-sticking part is arranged on a powder laying roller, a sealing cover is mounted on an operating panel, and a feeding sleeve, a telescopic sleeve and a feeding screw are arranged at the upper end of a sealing cover to achieve material-adding operation.