Abstract: A retainer is a ring around a central axis and includes an upper surface, a lower surface, an outside wall surrounding the central axis, and an inside wall surrounding the central axis. The outside wall is located at a side of the inside wall facing away from the central axis, the inside wall and the outside wall are respectively connected between the upper surface the lower surface. A plurality of grooves is formed on the outside wall and arranged at intervals along a circumferential direction of the outside wall. Each of the plurality of grooves communicates with the upper surface and the lower surface. The disclosure also provides an optical lens module having the retainer, and an electronic device having the optical lens module.