The invention discloses a
powder and
formaldehyde trapping device and a purifying method thereof. The purifying method comprises the following steps of engaging a power source of an exhaust fan, forming negative pressure in a lower box body, sucking the
waste gas into a water and
mixing chamber from an air inlet, and enabling the
waste gas to be in full contact with a
water curtain and water mist; then, enabling the
waste gas to pass under a second separating plate, penetrate out of water, and enter a water and air filtering chamber; in the ascending process, enabling the waste gas to encounter an inclined perforated water blocking plate, so as to automatically separate water and air; enabling air flow to quickly ascend, fully mix with negative
oxygen ions, and enter a centrifugal filtering chamber; filtering by a
filter element, and enabling the exhaust fan to exhaust clean air out of an air exhaust port. The purifying method has the beneficial effects that the fine dust PM2.5 (particulate matter 2.5) and
formaldehyde in the air, and more than 80 types of organic matters and inorganic matters which are dissolvable in water can be quickly trapped; the purifying accuracy is high, the amount of clean air is large, the amount of
consumables is small, the operation cost is low, the purifying device can be widely applied to the preventing and control of
air pollution sources and the control of decoration
pollution in medium and small production enterprises with low cost and high efficiency.