A multi-bit optical computing system, comprising: an optical source module for generating a light signal that contains optical signals of different frequencies; an optical path module, having an input terminal connected to the optical source module to receive the optical signals, and including a first optical path and a second optical path; an optical information storage module for receiving the optical signals via the first optical path, and containing a plurality of storage units (131, 132), each of the storage units (131,132) receives one of the optical signals to be stored as optical information; and an optical processing module connected to the optical information storage module via the second optical path, and receiving an external command; wherein the multi-bit optical computing system is characterized in that the optical processing module accesses the optical information in each of the storage units (131,132) simultaneously from the optical information storage module according to the external command, performs a command operation on the optical information stored in each of the storage units (131, 132), and outputs a plurality of output information, each output information corresponding to one of the plurality of storage units (131, 132); and the plurality of output information is transmitted via the second optical path to a corresponding one of the plurality of the storage units (131, 132) of the optical information storage module for storage; the multi-bit optical computing system further comprising: an optical path board, wherein the optical path module is formed on the optical path board through a photolithography and laser process or an etching process. an optical source module for generating a light signal that contains optical signals of different frequencies; an optical path module, having an input terminal connected to the optical source module to receive the optical signals, and including a first optical path and a second optical path; an optical information storage module for receiving the optical signals via the first optical path, and containing a plurality of storage units (131, 132), each of the storage units (131,132) receives one of the optical signals to be stored as optical information; and an optical processing module connected to the optical information storage module via the second optical path, and receiving an external command; wherein the multi-bit optical computing system is characterized in that the optical processing module accesses the optical information in each of the storage units (131,132) simultaneously from the optical information storage module according to the external command, performs a command operation on the optical information stored in each of the storage units (131, 132), and outputs a plurality of output information, each output information corresponding to one of the plurality of storage units (131, 132); and the plurality of output information is transmitted via the second optical path to a corresponding one of the plurality of the storage units (131, 132) of the optical information storage module for storage; the multi-bit optical computing system further comprising: an optical path board, wherein the optical path module is formed on the optical path board through a photolithography and laser process or an etching process.