The utility model relates to an online ladle heat accumulation roaster, including ladle, ladle lid, heat accumulation nozzle A, heat accumulation nozzle B, switching -over valve, heat accumulator C, heat accumulator D, its characterized in that: be provided with the ladle lid in the top of ladle, be provided with heat accumulation nozzle A, the heat accumulation nozzle B who erects in the upper end of ladle lid, pass through pipeline E, pipeline F and switching -over valve interconnect respectively in heat accumulation nozzle A, heat accumulation nozzle B's upper end, be provided with the heat accumulator C, the heat accumulator D that are provided with integrative preparation respectively on heat accumulation nozzle A, heat accumulation nozzle B's inner wall, the beneficial effects of the utility model are that: an organic whole is made with the heat accumulator to the heat accumulation nozzle, arranges in pairs and cover at the ladle that the high temperature section of heat accumulator is buried in the be built by contract to reduce heat loss, increasing the heat efficiency.