Abstract: A water-proof dust-proof and salty-mist proof cooling fan, comprising: a fan frame, which is provided with a fixing round stage inside, and a fixing sleeve is disposed in a center of said fixing round stage; a ring-shaped U slot is provided in a bottom end surface of said round stage, such that a sealing circle is provided in said ring-shaped U slot; a water-proof cover body, fixedly connected to said fan frame through said sealing circle; and a fan-blade hub, where an inverse cone-shaped fixing table is provided protruding from a cavity center of said fan-blade hub, and said fixing table is connected to a main axis. Said round stage is a blind hole, with its open end provided at a bottom portion of said fan frame, such that said round stage, said sealing circle, and said cover body together form a tight-sealing enclosure.