Chromium plating device for excircles of slender rod parts of air valves

The utility model provides a chromium plating device for an outer circle of a valve slender rod part. The chromium plating device comprises an upper insulating plate, a lower insulating plate and a connecting screw rod, the upper insulating plate and the lower insulating plate are connected into a whole through four connecting screw rods, and the distance between the upper insulating plate and the lower insulating plate is equal to the length of a rod part of a plating surface of a valve sample piece; an upper positioning hole and a lower positioning hole are correspondingly formed in the middle of the upper insulating plate and the middle of the lower insulating plate up and down respectively, a plurality of vertically-arranged lead anodes are evenly arranged between the upper insulating plate and the lower insulating plate, the upper ends of the lead anodes upwards penetrate through the upper insulating plate and are connected with a barrel lead belt, and the barrel lead belt is further connected with a cop