Embodiments of the present disclosure disclose an image data processing method performed at a computing device, including: obtaining target image data, and creating grid information on a target display region corresponding to the target image data; obtaining a sliding operation track corresponding to a touch screen, and extracting a touch point in the sliding operation track, as a target touch point; creating position coordinates of the target touch point, and calculating, according to the grid information and the position coordinates of the target touch point, a cleaning number corresponding to the target touch point; adding a grid number same as the cleaning number to a preset number set, and deleting subimage data covered by the target touch point; and completely deleting, when the quantity of grid numbers in the number set meets a cleaning condition, the target image data from which a plurality of pieces of subimage data has been deleted.