The invention belongs to the technical field of spraying equipment, and particularly relates to a uniform spraying device for a curved-surface plate. The uniform spraying device comprises a support part, a suspension part, a spraying mechanism and a rubber guide rail. According to the uniform spraying device for the curved-surface plate, a piston rod of a support cylinder drives the curved-surface plate to move upwards, so that a curved surface matched with the curved-surface plate is formed on the bottom surface of the rubber guide rail, after the matched curved surface is formed, a piston rod of a tensioning cylinder tensions a tension rope, a metal sheet is enabled to be attached to a rubber sheet, the rubber sheet is tightly attached to a hanger rod, the friction force between the rubber sheet and the hanger rod is increased, the hanger rod is locked, the lower end of the hanger rod is connected with the rubber guide rail, the bottom surface of the rubber guide rail is matched with the surface of the curved-surface plate accordingly, after the hanger rod is locked, the piston rod of the support cylinder drives the curved-surface plate to move downwards, the distance between the curved-surface plate and the spraying mechanism is the spraying distance, the vertical distances between the spraying mechanism and all the positions of the curved-surface plate are equal in the spraying process, then uniform spraying of the curved-surface plate is achieved, and the spraying quality is improved.