The invention discloses a coating device and a coating method of a curved-surface cover plate as well as a readable storage medium. The coating device comprises a sputtering mechanism used for spraying a coating material in a predetermined direction at a certain sputtering rate, a moving mechanism used for driving the curved-surface cover plate to move and successively moving different coating areas on the curved-surface cover plate to the predetermined direction, and a correcting nozzle used for successively correcting the coating material from the sputtering rate to a coating rate corresponding to a coating area in the predetermined direction, wherein the correcting nozzle comprises an incoming opening, an outgoing opening and a cavity used for connecting the incoming opening with the outgoing opening; the incoming opening is sleeved on a target nozzle of the sputtering mechanism; the outgoing opening faces to the curved-surface cover plate; the size of the outgoing opening of the correcting nozzle can be adjusted; the coating material is corrected from the sputtering rate to the coating rate corresponding to the coating area in the predetermined direction by adjusting the size of the outgoing opening. The coating device is capable of solving the problem of non-uniform coating of the curved-surface cover plate and improving the quality of images of curved-surface display screens.