An adjustable optical lens and camera module, and manufacturing method and applications thereof is disclosed. The camera module includes an optical sensor and an adjustable optical lens. The adjustable optical lens includes an optical structural member and at least two lenses, wherein each of the lenses is arranged in an internal space of the optical structural member. Along a vertical direction of the optical structural member, at least one lens is adapted to be adjustably pre-mounted to an internal space of the optical structural member serving as an adjustable lens. The side wall of the optical structural member is provided with at least one adjustment channel, which is positioned corresponding to the adjustable lens, so that an assembling position of the adjustable lens can be adjusted through the adjustment channel so as to align a central axis line of the adjustable optical lens with a central axis line of the optical sensor.