A lens module includes a circuit board, a hollow mounting bracket, a photosensitive chip, a lens base, and a lens. The photosensitive chip is mounted within the hollow mounting bracket on a surface of the circuit board. The lens base is mounted on a surface of the mounting bracket opposite to the circuit board. The lens base axially defines a through hole. The lens is mounted within the lens base. The lens base includes a screw thread formed along an inner wall of the through hole. The lens includes mating threads formed along a periphery of the lens contacting the inner wall of the through hole. The mating threads define at least one thread slot which defines a gap with the screw threads of the inner wall of the through hole.