The invention discloses a coating device for metal bottles. The coating device comprises a transmission unit, a coating pool, a washing pool, a capture unit, a drying unit and a control system; the coating pool and the washing pool are arranged up and down, the transmission unit is partially located in the coating pool and partially located in the washing pool, the drying unit is located at the right end of the coating pool, and the capture unit is located above the drying unit and the tail of the transmission unit; and the coating pool is filled with a protection material, the washing pool is filled with washing liquid, and the control system is electrically connected with a first driving device of the transmission unit and a second driving device of the capture unit so as to control running of the transmission unit and the capture unit. The coating device is provided with the coating pool and the washing pool, after being coated with the protection material in the coating pool, the metal bottles enter the drying unit to be dried with hot air, and protection layers are arranged on the outer surfaces of the dried metal bottles; and the coating device is simple in structure and higher in coating efficiency, and the coating cost is reduced.