Plastic spraying cable tray is a surface treatment method to spray plastic powder on the cable tray. No dilution, the construction of the environment without pollution, non-toxic to human body; coating appearance of excellent quality, adhesion and mechanical strength; spraying construction curing time is short; coating corrosion and abrasion resistance is much higher; do not need primer; construction is simple, low technical requirements of workers; cost lower than the spray paint process; some construction occasions have been explicitly proposed must be used in electrostatic spraying process; electrostatic spraying process will not occur in the spraying process. The common phenomenon of flow in the paint spraying process. Is the use of corona discharge phenomenon so that the powder coating adsorption on the cable tray. The process is this: powder coating from the powder supply system by compressed air gas into the spray gun, in the front of the gun with a high-voltage electrostatic generator generated by the high voltage, due to corona discharge, in the vicinity of which a dense charge, powder sprayed by the gun nozzle, the formation of charged paint particles, which is subject to the role of electrostatic force, was sucked into the workpiece with its polarity opposite to the workpiece to go up, with the increase in the powder sprayed on the increase in the accumulation of electric charge is also more and more when the powder is sprayed on a certain thickness, due to the generation of electrostatic force, when it reaches a certain thickness, it will not flow. When it reaches a certain thickness, due to electrostatic repulsion, it will not continue to adsorption, so that the whole workpiece to obtain a certain thickness of powder coating, and then after the heat so that the powder melting, levelling, curing, that is, in the surface of the workpiece to form a hard coating film.