A bulk curing barn with a steam damp replenishing and thermal moisture regaining system comprises heating rooms and baking rooms and also comprises a humidifying system and a hot steam moisture regaining system; the humidifying system comprises a pressure tank, a water pump, a total pipe and branch pipes for connecting the total pipe with the heating rooms; the water inlet end of the pressure tank is connected with the water pump; the pressure tank is connected with a reservoir by the water pump; the water outlet end of the pressure tank is connected with the total pipe. Each branch pipe is provided with a branch solenoid valve and a hot steam connecting pipeline; each branch solenoid valve is electrically connected with a controller by a driving circuit; each controller is connected with a microprocessor and a humidity sensor arranged in the corresponding baking room by a signal line. The hot steam moisture regaining system comprises a steam generator; the hot steam of the hot steam generator is connected with a hot steam connecting pipeline by a hot steam pipeline; a water inlet pipe is arranged at the bottom of the steam generator; the steam generator is connected with the reservoir by the water pump. The problem of regulation difficulty on the humidity in the baking room is solved, and the moisture regaining problem of baked tobaccos is solved.