Electrophotrsis coating process, the most advanced manufacturing technique in current coating industry, has the feature of incomparable advantages such as less pollution than traditional solvent-based coating.Especially CED (Cathodic Electro Deposition), which is widely used in primer coating of automobile and engineering machinery industry. The principle of this coating method is take advantage of clcett7c field to make panicles such as paint and resin that suspending in electrophoresis liquid migrate directionally and precipitate in electrode basal surface. It is a kind of equipment with low pollution, high safety, degree of automation, anti-corrosive, and utilization ratio, etc.