Abstract: A light detection module includes: a TO base and a TO cap; wherein the TO base is fixedly provided thereon with a first optical sensor, a support frame and a support base; the support frame is fixedly provided thereon with a beam splitter, and the beam splitter and the first optical sensor are at an angle of 45 degrees; an upper surface of the support base is fixedly provided thereon with an optical resonator and a second optical sensor, the optical resonator is located between the beam splitter and the second optical sensor, and the optical resonator, the second optical sensor and the beam splitter are on a straight line parallel to a surface of the TO base; and the TO cap is provided thereon with an opening, and the opening, the first optical sensor and the beam splitter are on a straight line perpendicular to the surface of the TO base.