Automatic paint spraying device of inner wall

The invention provides an automatic paint spraying device of an inner wall used for low viscosity paint spraying. The automatic paint spraying device comprises a spraying car (3), a funicle cable (4), a spraying car guiding unwheeling (5) and an electrical controlled cabinet (6). The spraying car (3) is operated in a metal circular tube product (1). The spraying car (3) is composed of an underpan, a walking driving system, a paint spraying system, a pneumatic control system and a protecting cover. The spraying car (3) is controlled by the walking driving system to walk along the forward direction and the backward direction of the spraying car guiding unwheeling (5). Automatic open and close of a spray gun by the paint spraying system is achieved through the pneumatic control system, and therefore the automatic paint spraying to the inner wall of the metal tube (1) is achieved. Paint supplying, open and close of the spray gun and adjustment of spray range of a fan face are achieved by the pneumatic control sys