The invention discloses a barrel plating device. The barrel plating device comprises a left support plate, a right support plate and a control box; a roller tooth disc is arranged on the left support plate; a driving tooth disc is arranged on the left support plate; round holes are uniformly formed in the roller tooth disc; a metal isolation cover with one end inserted in the round holes is further provided; an insulation pipe is arranged on the outer side of the metal isolation cover; a driving motor and a rotating motor are arranged in the control box; the rotating motor enables the insulation pipe to rotate through a transmission belt; an electric conducting ring is embedded in the roller tooth disc; the end part of the metal isolation cover is inserted in the round holes, and abuts against the electric conducting ring; and a cathode electric conducting wire is arranged on the control box. The barrel plating device is simple in structure, greatly improves the electroplating efficiency, guarantees the electroplating stability and uniformity, and solves the technical defects of low efficiency, weaker quality and high cost in a traditional electroplating mode adopted by larger parts in the prior art. Meanwhile, the invention discloses an operation method of the barrel plating device; and the method is simple and fast in operation, and can greatly improve the electroplating efficiency and the quality stability.