A washing machine comprising a steam generating device, wherein the steam generating device comprises: a heating control unit, a heating pipe connected to the heating control unit, a steam heating chamber arranged around the heating pipe, and a cover plate component for facilitating escaping of steam and supplementation of cold water and arranged above the steam heating chamber; wherein, the heating control unit comprises a heating control circuit, a control piece, and a level gauge arranged in the steam heating chamber for preventing dry-fire of the heating pipe; the control piece is connected with the heating control circuit, the level gauge and the heating pipe respectively; the level gauge transmits a liquid level value measured in real time to the control piece; when the liquid level value is lower than a preset safety value, the heating control unit stops heating to prevent dry-fire of the heating pipe; and when the liquid level value is greater than the preset safety value, the heating control unit controls the heating pipe to continue to operate; and the heating pipe is arranged on a bottom of a rear outer drum of the washing machine, the steam heating chamber is formed partially on an inner surface of the rear outer drum, and kept sealed except top and side openings; slots are formed respectively at top portions of both side walls of the steam heating chamber; the cover plate component is inserted on a top portion of the steam heating chamber through the slots and the steam heating chamber is kept in a closed state; characterized in that the cover plate component comprises a side plate and a top plate, which are connected to each other; and the side plate and the top plate are respectively adapted with the side opening and the top opening of the steam heating chamber; and when the cover plate component is inserted into the top portion of the steam heating chamber, the top plate is arranged on the inner surface of the rear outer drum; the top plate is further provided with a plurality of steam discharging ports for discharging heated steam, the side plate is further provided with a plurality of water flow exchange ports for introducing an external water flow with negative pressure. wherein, the heating control unit comprises a heating control circuit, a control piece, and a level gauge arranged in the steam heating chamber for preventing dry-fire of the heating pipe; the control piece is connected with the heating control circuit, the level gauge and the heating pipe respectively; the level gauge transmits a liquid level value measured in real time to the control piece; when the liquid level value is lower than a preset safety value, the heating control unit stops heating to prevent dry-fire of the heating pipe; and when the liquid level value is greater than the preset safety value, the heating control unit controls the heating pipe to continue to operate; and the heating pipe is arranged on a bottom of a rear outer drum of the washing machine, the steam heating chamber is formed partially on an inner surface of the rear outer drum, and kept sealed except top and side openings; slots are formed respectively at top portions of both side walls of the steam heating chamber; the cover plate component is inserted on a top portion of the steam heating chamber through the slots and the steam heating chamber is kept in a closed state; characterized in that the cover plate component comprises a side plate and a top plate, which are connected to each other; and the side plate and the top plate are respectively adapted with the side opening and the top opening of the steam heating chamber; and when the cover plate component is inserted into the top portion of the steam heating chamber, the top plate is arranged on the inner surface of the rear outer drum; the top plate is further provided with a plurality of steam discharging ports for discharging heated steam, the side plate is further provided with a plurality of water flow exchange ports for introducing an external water flow with negative pressure.