In fact, these welding methods for different welding materials, welding material thickness has different applicable conditions, such as if the welding thickness of steel, laser welding is more beautiful, can be formed once, high strength, but there may be spatter.The welding quality of plasma welding is better than that of gas welding.Such as brazing welding method is commonly used in dissimilar metal welding, according to its bond strength solder and decided to lower than the same general metal welding strength, but the good weld forming pressure welding is similar to the resistance welding, friction welding, the common forming effect is good, the strength of the friction welding is higher than the intensity of spot welding in fact this comparison between several kinds of welding methods can't unity, should according to the material, process, production conditions to compare.