A thermal management device and a battery pack are provided. The thermal management device applied in a battery pack. The battery pack includes a case and a plurality of cells received in the case. The thermal management device includes: a thermal management loop attached to each cell and at least partially covering a part of a vent of each cell; a heat exchange member communicating with the thermal management loop; and a power component connected between the thermal management loop and the heat exchange member. A heat exchange medium with a fire-extinguishing function is provided within the thermal management loop. The thermal management loop is broken in a condition where at least one cell is subjected to thermal runaway such that the heat exchange medium flows into an explosion-proof port of the at least one cell.