When the laser energy density is too high, the radius of the molten pool becomes too large, the metal powder entering the molten pool increases in unit time, and the width of the molten channel increases. However, due to too much powder on both sides entering the melting pool, when the scanning interval is too small, no powder will melt in the next laser, and only the formed one can be remelted. As a result, the area on one side of the first laser will sag, and new metal powder will be available when the third or fourth melting is carried out.