Water-based paint coating device for back paint of metal building materials

The utility model discloses a metal building material back paint water-based paint coating device which comprises a coating machine body, the bottom of the coating machine body is fixedly connected with a base, and the top of the inner wall of the base is fixedly connected with a top plate. When other places needing to be sprayed need to be sprayed, the handle is rotated, the handle drives the threaded rod to rotate, the threaded rod drives the push plate to move backwards, the push plate drives the first moving block to move backwards, the first moving block drives the first rotating plate to turn over downwards, the first rotating plate drives the second rotating plate to turn over downwards, and the second rotating plate drives the second moving block to move backwards. A second moving block drives a second vertical plate to move downwards, the second vertical plate drives a bottom plate to move downwards, the bottom plate drives pulleys to move downwards, the pulleys make contact with the ground, and then