The invention discloses a feeding device of a coating machine. The feeding device comprises a shell, a feeding outlet, a storage box and a feeding box. The feeding box is arranged in the shell. A heat insulation layer is fixed between the feeding box and the shell. The upper end of the shell is rotationally connected with a sealing cover through a hinge. The outer wall of the shell is provided with a controller. A feeding pump is fixed inside the feeding box, and the upper end of the feeding pump is connected with a feeding pipe. The other end of the feeding pipe penetrates through a feed inlet to be connected with the storage box. The lower end of the feeding box is provided with the feeding outlet. A fixing frame is fixed between the feeding box and the feeding outlet. A motor is fixed to the upper end of the fixing frame. The motor is rotationally connected with a spiral blade through a rotating shaft. The bottom of the feeding outlet is provided with a control valve. The control valve, the motor, the feeding pump and a liquid level meter are electrically connected with the controller through wires. Materials in the storage box are pumped into the feeding box through the feeding pump, time and labor are saved, discharging is made uniform through the spiral blade in the feeding outlet, and use is convenient.