The invention relates to a multi-functional ventilation fan comprising a machine body, a mask, a heat exchanger, a blower and a compressor, wherein the mask is provided with an air suction opening and an air outlet, and the heat exchanger, the blower and the compressor are arranged in the machine body. The multi-functional ventilation fan is characterized in that the inside of the machine body isdivided into a first area, a second area and a third area which are spaced and formed by a plurality of baffle plates, wherein a first heat exchanger and a ventilation air blower are arranged in the first area, and an exhaust opening of the ventilation air blower is communicated with the outside; a second heat exchanger and a circulating air blower are arranged in the second area; a compressor isarranged in the third area; the air suction opening of the mask and the first area are communicated to form a first air passage; and the air suction opening of the mask, the first area, the second area and the air outlet of the mask are sequentially communicated to form a second air passage, a first valve used for isolating the first area is arranged in the second air passage, and the air suctionopening of the mask, the second area and the air outlet of the mask are sequentially communicated to form a third air passage. The invention can realize a plurality of functions of ventilation, dehumidification, heat generation, refrigeration and the like.