The invention relates to an automatic paint spraying device and automatic paint spraying method for an inner wall of a wind-powered electricity-generation tower pole. The automatic paint spraying device comprises a walking wagon, a supporting frame, a spray gun, a control cabinet, a fixing frame, a feed valve, a rotating valve, a hollow rotating shaft and a motor, wherein the motor is fixedly connected to the supporting frame and drives the hollow rotating shaft to rotate; the rotating valve is fixed to the supporting frame through the fixing frame; the feed valve is connected with the hollow rotating shaft through the rotating valve, and provides a material circulating channel, and the other end of the hollow rotating shaft is connected with the spray gun, and is used for enabling materials to be sprayed from a nozzle of the spray gun; the motor is in signal connection with the control cabinet; and the walking wagon is in signal connection with the control cabinet. The automatic paint spraying device disclosed by the invention is high in efficiency, good in paint spraying effect, uniform in paint spraying thickness, and suitable for paint spraying for the inner wall of a large-diameter steel pipe of which the diameter is 3-10 m; microcomputer control is adopted to realize automatic operation, and manual operation is not needed; the weariness of an operator is relieved, and the working efficiency is improved; the coating is level, smooth, and free from brush marks; and paint is saved.