The invention provides a sliding groove type sealing device on the upper portion of a ring-cooling machine trolley. The sliding groove type sealing device comprises a dust cover support, an asbestos sealing plate and an elastic sealing sliding groove assembly, wherein a support oil tube hole is formed in the center of the dust cover support, and an oil tube is arranged in the support oil tube hole to provide lubricating grease; the upper portion of the asbestos sealing plate and the dust cover support are together fixed to a ring-cooling machine smoke hood together, and the lower portion of the asbestos sealing plate is provided with a plate matched with the side face of the upper end of a side plate of the ring-cooling machine trolley in shape; and the elastic sealing sliding groove assembly is fixed to the dust cover support and composed of an upper plate shell, an inner groove plate, an inner core plate, a spring assembly and steel wire brushes. The groove type sealing plate is adopted, the lubricating grease is used for lubricating prone-to-wearing potions of the device, so that a good sealing effect is achieved; the flexible steel wire brushes are additionally mounted on the two sides of the sealing device to achieve effective separation of the sealing device; the sealing device is composed of an upper part and a lower part, and two spring assemblies are located in the middle to achieve the elastic compensation effect; the inner core plate is hung on the lower side through a pin, the bottom face of the inner core plate is tightly attached to the upper end face of the side plate of the ring-cooling machine trolley, and sealing and lubricating are achieved under the effect of the lubricating grease.