The invention relates to the field of light-catalyzed reaction hydrogen production and light-catalyzed methyl alcohol and oxygen production, and in particular relates to a light-catalyzed reaction system for collecting sunlight. The light-catalyzed reaction system mainly comprises a light collector, a light conduction device and a light transmitting reactor capable of transmitting full-spectrum rays of the sunlight, wherein the light collector is fixed at the free end of a two-degree-of-freedom bracket formed by connecting a pitching main shaft with an orientation main shaft; the orientation main shaft and the pitching main shaft can be driven respectively by self servo motors to relatively rotate to track the sun; converging rays formed by transmission and convergence of the sunlight collected by a light collecting convex lens group through the light conduction device are directed to the light transmitting reactor; the light transmitting reactor consists of a light transmitting cylinder and a sealing cover; the sealing cover is arranged on the light transmitting cylinder; a reaction solution is filled in the light transmitting cylinder. The sunlight can be automatically tracked, and can be conveniently transmitted to an indoor light reactor without barriers, and light-catalyzed reaction hydrogen production and light-catalyzed methyl alcohol production processes can be truly carried out in a full-spectrum band of the sunlight.