In this paper, the influence of surfacing technology and material on the quality of light beam Ni based alloy powder surfacing layer was investigated. In order to acquire surfacing layer of quality, the width of pre coating must be smaller than that of light spot. Too big thickness of pre coating can result in the poor bond between surfacing layer and base metal. While the pre coating is too thin, the macrohardness of surfacing layer decreases obviously owing to high dilution of base metal. By means of multi layer and multi pass lap surfacing, the surfacing layer with big thickness and area can be acquired. The transverse crack in surfacing layer, porosity in bead edge and non fusion between layers are the defects that are liable to produce when multi layer surfacing is used. When multi pass lap surfacing is used, non lap in the toe of weld can arise because of selected moisture. The reasonable control of heat input, cleaning of former weld and good protection of molten pool are the crucial factors of acquiring surfacing layer with big thickness and area. When adding wettable ceramics (WC with Ni coating) with Ni-based alloy and controlling the content of WC with Ni coating, the high quality of surfacing layer with higher hardness can be acquired.