A gas purifying device for an air-conditioning terminal product includes a housing; an ion generator secured to the housing; blades arranged on the outer side of the housing and used for receiving wind power from the air-conditioning terminal product for rotation; and an electric generator arranged in the housing and connected to the blades through a rotor shaft; when rotating, the blades drive the electric generator to operate to convert wind energy into electric energy, thereby enabling the electric generator to supply power to the ion generator. An air-conditioning terminal product provided with the gas purification device, and an air-conditioning unit configured with the air-conditioning terminal product.