This paper fabricated pure tungsten thin wall parts by laser single track scanning via SLM. The wall thickness and molten trace width were measured by two-dimensional imager and optical microscope, respectively, and the influence of laser power and scanning rate on the wall thickness and molten trace width were investigated. The surface 2D and 3D morphology of thin walls were detected by optical microscope. The powder adhesion on the side surface of the thin wall was detected by scanning electron microscope and the reason for powder adhesion was analyzed. The results indicated that the walls thickness was greater than molten trace width. With the increase of laser power, the wall thickness amd molten trace width increased, the surface of thin wall became smooth. With the increase of scanning rate, the wall thickness and molten trace with decreased, the molten trace became twisted first and then straight, and twisted again, the height difference of the molten trace decreased first and then increased. The thin wall consisted of complete melting zone, balling zone, semi-melting zone and unmelted zone.