According to the theory of modern welding, welding defects in the weld pool, the ability to maintain good weld pool state is an important symbol of the welding level. On the other hand, the welding since closing arc, respectively, in the formation of the molten pool and the end of the welding defects occur during the maximum probability of two. The ordinary traditional mask the following defects: Drawbacks: using ordinary black glass lenses, particularly from the arc during the blind welding, bare welding inevitable, welding will be for a long time to accelerate the fatigue and injuries of the welder while and will affect the efficiency and quality of the welding operation, and also inevitably caused the welding material waste and repair rate of high; Drawbacks: ordinary traditional mask used in the black glass lens can only absorb the welding glare, and can not filter the welding when a large number produced by infrared, ultraviolet, the formation of secondary radiation, the infrared radiation can cause cataracts; ultraviolet interested cornea of ​​the eye and The hazards of the lens, causing blindness and cataracts, usually also may lead to dermatitis, skin cancer; Drawbacks: the ordinary traditional mask monochrome No. can not be provided to the the job observations darkness greatly influence the formation of the observation of the weld pool control and good weld, causing slag, undercut , porosity, lack of penetration and weld cracking, destruction of non-welded surface smoothness and roughness defects affecting welding the total yield.