The invention discloses a spraying method. A novel spraying device is used in the method. The device comprises a base; a liquid storage box is mounted on the base; an aerosol valve is mounted on the liquid storage box and is connected with a spraying gun head; a vertical sliding seat is mounted on the base; a first transmission shaft is mounted on the vertical sliding seat; a first servo motor isconnected at one end of the first transmission shaft; a first supporting arm is connected at the other end of the first transmission shaft; the axis of the first transmission shaft is consistent withthe extending direction of the first supporting arm; a second transmission shaft driven by a second servo motor is mounted at one end of the first supporting arm; the second transmission shaft is connected with a second supporting arm; the axis of the second transmission shaft is perpendicular to the axis of the first transmission shaft; the spraying gun head is mounted at one end of the second supporting arm; a first locking structure is arranged between the first supporting arm and the vertical sliding seat; and a novel second locking structure is arranged between the first supporting arm and the second supporting arm. The spraying method has the bright application prospect and popularization potential in multiple fields.