The utility model discloses a system for collecting, conducting and utilizing light rays. The system comprises a light collector consisting of a convex lens and a concave lens, an optical fiber, a light diffuser consisting of a convex lens and a concave lens, an auxiliary accessory switchgear and a light ray reflector, and is characterized in that the light rays are collected from a light source at a larger-area periphery by the light ray reflector, are reflected to the light collecting surface of the light collector and are directly emitted to the light collector; after being refracted in the light collector consisting of the convex lens and the concave lens, the light rays are conducted to a position needing to be irradiated by the light rays through the optical fiber in a centralized way, are diffused and emitted by the light diffuser consisting of the convex lens and the concave lens, and are utilized; the switchgear is arranged in the optical fiber and can refract and reflect the light rays to interrupt the transmission and irradiation of the light rays. The system for collecting, conducting and utilizing the light rays is environmentally-friendly, economical and practical.