An ultra-fast wide-temperature-range thermal device and a method, belonging to the technical field of high-temperature thermal equipment and material preparation. The thermal device comprises a furnace body unit, a temperature field monitoring unit, a linkage control unit and a heating and heat preservation structure unit, the heating and heat preservation structure unit comprising a surrounding area (31), a current load core area (32) and electrodes (21), the surrounding area (31) being arranged on the periphery of the current load core area (32) and the electrodes (21), and the current load core area (32) being arranged in a gap between the electrodes (21). The electrodes (21) can, by means of their own displacement, perform real-time regulation and control on the density of conductive powder (20) in the current load core area (32). The temperature field monitoring unit monitors in real time the temperature of the heating and heat preservation structure unit, and the linkage control unit compares the real-time temperature data with a preset time-temperature curve, and regulates the displacement or current load of the electrodes (21) according to a comparison result, thus achieving real-time dynamic visual monitoring and accurate regulation and control of the whole-domain temperature field of a conductive powder bed in the whole process.