Abstract: The used magnesia-based coating of the tundish was recycled and processed to make light-burned magnesia balls, and the recycling and utilization technology of the used magnesia-based coating of the tundish was studied. Through the performance testing and analysis of the prepared light-burned magnesia balls, as well as laboratory experiments and field tests, it was shown that the unsintered part of the used magnesia-based coating of the tundish, after being recycled and processed to make light-burned magnesia balls, had physical and chemical properties meet the requirements of the converter charge index. The MgO content in the formed slag is higher than that in the slag formed by using dolomite for magnesia burdening, and the basicity of the slag was also slightly higher. The prepared light-burned magnesia balls could provide more MgO to the slag, and the effect of mixing magnesia to make slag was better. It could completely replace caustic calcined dolomite, etc. as a converter final slag modification agent and be used in the converter magnesia burdening and slag making process and the slag splashing furnace protection process. It could fully inhibit the dissolution and diffusion of MgO in the furnace lining into the slag, playing a role in protecting the furnace lining. In addition, the light-burned magnesia balls made from the used magnesia-based coating of the tundish had a fast slag formation speed. Compared with the dolomite slag making process, the slag formation speed was about 1 to 2 minutes earlier. The used magnesia-based coating of the tundish had a high recycling and utilization value as a charge in converter steelmaking.