The invention provides a steam drier comprising a furnace body, a water tank and a water pump, the water tank is connected with the water pump through a first pipeline, the water pump is connected with the furnace body through a second pipeline, the interior of the furnace body is provided with an electric heater unit, the upper part of the furnace body is provided with a steam outlet pipeline, and the water tank is provided with an inlet pipeline. The steam drier is characterized in that the furnace body is inside provided with a water level sensor, the water level sensor and the electric heater unit are in data connection with a controller, and the controller automatically controls heating power of the electric heater unit according to the measured water level in the furnace body. According to the invention, intelligent control of the heating power of the electric heater unit in the steam drier is achieved through water level detection, and therefore stable water level is maintained, the outgassing rate is increased, and the intellectualization degree is improved.