The invention discloses a spraying instrument special for a waterproof heat-preservation outer wall coating. The spraying instrument comprises a cart and a taking and placing device, wherein one side, close to a first threaded rod, of the cart is connected with a first guide rod, and the taking and placing device is fixed on one side of a binding device. According to the spraying instrument special for the waterproof heat preservation outer wall coating, a spraying device is arranged, the coating in a three-way pipe enters a hose through a conveying pipe, then enters a spraying head at one end through the hose and is sprayed out through a mist spraying opening in one side of the spraying head, a third threaded rod is rotated, the third threaded rod drives the spraying head to move in the direction of a second guide rod, the spraying head moves to extrude sealing gaskets on the two sides, pressure borne by the sealing gaskets is transmitted to a stopping block, the stopping block is stressed to extrude a third spring to enter a groove, the number of spraying nozzles blocked by the sealing gaskets is smaller and smaller, the number of spraying nozzles capable of being sprayed is larger and larger, the spraying area is increased due to the increase of the number of the spraying nozzles, and the spraying area is convenient to control.