Device and method for heating fused salt

The invention relates to a device and method for heating fused salt. The device comprises a first fused salt tank, a second fused salt tank, at least one fused salt electrode, at least one inlet electrode isolation pipeline, at least one outlet electrode isolation pipeline, at least one first connecting pipeline, at least one second connecting pipeline, at least one first fused salt circulating pump and a power source device, wherein each fused salt electrode comprises a plurality of fused salt electrode boxes; the first fused salt circulating pumps are arranged in the corresponding first connecting pipelines and used for pumping the fused salt in the first fused salt tank into the fused salt electrode boxes; the power source device comprises multiphase alternating current; the number of the phases of the multiphase alternating current is identical to the number of the fused salt electrode boxes; and each phase of the multiphase alternating current of the power source device is connected to the corresponding