The invention discloses a fresh air unit installed outdoors. The fresh air unit installed outdoors comprises a body, an upper cover, a fixing support and an air feeding device. The air feeding device comprises a first grating, a first filtering device, a heat exchanger, a first air hose, a first draught fan, a second draught fan, a second air hose, a second filtering device and a second grating. The first grating and the second grating are arranged at the bottom of the body. The heat exchanger, the first filtering device, the first air hose, the first draught fan, the second draught fan, the second air hose and the second filtering device are all arranged in the body. The upper cover is installed on the front side of the body, and the fixing support is installed at the back of the body. In this way, the fresh air unit installed outdoors breaks through an installing mode and a working mode of a traditional fresh air unit, indoor noise is substantially lowered, repair and maintenance are convenient, the using range is wide, the fresh air unit installed outdoors can be used even though in a severe cold area, and the using effect is better.