The invention discloses a supercritical electronic injection flash boiler. The supercritical electronic injection flash boiler is composed of a fused salt adding pipe, a fused salt groove, a fused salt discharge pipe, an insulating layer, a burning cavity, a smoke pipe, a smoke cavity, a burning machine, a waste heat recovery water tank, a water outlet pipe, a high pressure plunger pump, a high pressure spray mist device, a steam generator, a first steam coiler, a second steam coiler, a third steam coiler, a steam groove, a steam header, a smoke discharge pipe, a water inlet pipe, a first smoke groove, a second smoke groove, an air pipe, a water groove, a turbine, a power generator, a first electric heater and a second electric heater. The supercritical electronic injection flash boiler has the beneficial effects that vapor and mist jetting water feeding is adopted, the heat-exchange surface is enlarged, and the heat efficiency is improved; the temperature difference of entering vapor mist and pipe heat generates gas explosion so as to generate the dynamic effect, gas expansion is increased, superheated steam is directly and quickly generated, steam temperature and pressure are adjustable, and the superheated steam is directly produced; and steam temperature and pressure are adjustable.