The invention discloses a hull plate paint-spraying wall climbing vehicle device carried on an aerial lift vehicle and a work method thereof, and belongs to the technical fields of naval architecture and ocean engineering and machinery automation. According to the hull plate paint-spraying wall climbing vehicle device, a wall climbing vehicle carries spraying nozzles to carry out spraying operation, so that labor intensity is lowered. A multi-spraying-nozzle spraying mode is adopted, so that the work efficiency is improved by many times, and the work period for hull plate spraying is shortened. A paint mist recovery cover mechanism adopted above the spraying nozzles can effectively suck paint mist generated in the spraying process through negative pressure, so that the toxic action of the paint mist to operators is reduced. The aerial lift vehicle is connected with the wall climbing vehicle, so that the load bearing capacity of the wall climbing vehicle is remarkably improved, the risk of accidental falling of the wall climbing vehicle can be completely eradicated, and the safety of the wall climbing vehicle during spraying operation is increased. A material supply cart integrating a stirring function, a material supply function and a paint mist recycling function is mounted on the rear portion of the aerial lift vehicle and can automatically complete the operation of paint pumping from a paint barrel, stirring, material supply and paint mist recycling, and direct contact between the operators and paint is reduced.