The invention belongs to the technical field of vertical rolls, and discloses a device for improving surface quality of a vertical roll of a vertical rolling mill. The device comprises an oil water mixing and spraying structure and a roll surface spraying-blowing structure, wherein the output end of the oil water mixing and spraying structure is arranged towards the roll surface of the vertical roll; covering height of a sprayed and covered surface is greater than or equal to height of a contact surface between the vertical roll and plate blank; the roll surface spraying-blowing structure comprises a spraying-blowing spray head, a gas-flow pipeline and a gas source; the spraying-blowing spray head is connected with the gas source through the gas-flow pipeline to obtain compressed air; andthe spraying-blowing spray head is arranged towards the roll surface of the vertical roll for spraying and blowing compressed air to the roll surface. The device for improving surface quality of the vertical roll of the vertical rolling mill provided by the invention can improve the surface quality of the vertical roll.