The invention discloses a spray device special for cleaning the outer wall of a tall building. The spray device comprises a control panel, a
high pressure spray gun and a base, wherein a support bottom rod and a fixed rack are arranged below the base, movable rollers are arranged at two sides of the fixed rack, a box body is arranged above the base, a
water storage box is arranged in the box body, and an
electric control valve is arranged in front of the
water storage box. The spray device disclosed by the invention is scientific and reasonable in structure and safe and convenient to operate; a flow control hole and an
electric control door are arranged in a mixing box, a detergent
solvent tank is arranged at the top of the mixing box, and by using the flow control hole and the
electric control door, a detergent
solvent can be automatically added into the mixing box, and the quantity of the detergent
solvent can be controlled; a
supercharger is arranged in the mixing box, and the use of the
supercharger can improve the spraying efficiency; and a
nozzle is arranged in the
high pressure spray gun, and the use of the
nozzle can realize uniform spraying of the solvent.