Metal 3D printing method and residual powder cleaning process

The invention discloses a metal 3D printing method and a residual powder cleaning process, and relates to the technical field of 3D printing, the metal 3D printing method comprises a rack, a platform mechanism and a cleaning mechanism, an inner frame is fixedly mounted in the rack, the platform mechanism is arranged in the inner frame, the cleaning mechanism is arranged on the inner frame, the platform mechanism comprises a mounting plate and a printing platform, and the printing platform is arranged on the mounting plate. A first servo motor is fixedly mounted on the mounting plate, a threaded rod is fixedly mounted at the output end of the first servo motor, and a threaded cylinder is fixedly mounted at the bottom of the printing platform. After the printing platform descends to the lowest point of the stroke, a second servo motor is started to drive a lead screw to rotate, a push plate moves leftwards, residual powder on the printing platform is pushed, the residual powder is pushed out through a material