The invention discloses a pre-heating and heating device of a high-temperature molten salt storage tank. The pre-heating and heating device comprises a tank wall electric heat tracing, a tank bottom electric heat tracing, an air gathering pipe, a circulating fan, an air door regulator, a fixed type spiral nozzle, a rotation type nozzle and an air channel, and the pre-heating and heating device combines tank body pre-heating and a storage medium together. The electric heat tracings are arranged at the tank bottom and the tank wall, the electric heat tracings heat the tank body metal and conducts heat preservation in the pre-heating process of the tank body, the temperature of the tank wall is cooled and balanced through a closed type circulating air system, meanwhile, the circulating air isheated, and the circulating hot air reheats the tank top and the tank bottom. The electric heat tracings heat molten salt to maintain the temperature of the medium in the long-time break down. The pre-heating and heating device avoids that a conventional electric heating bar sleeve pipe conducts trepanning at the bottom of the tank wall, so that the risk that the storage tank leaks is reduced. Meanwhile, a high-power air heater does not need to be configured. The pre-heating efficiency and the operation reliability of the storage tank are improved.