The invention discloses a wave length mutual multicasting type process level optical network structure. The wave length mutual multicasting type process level optical network structure is characterized in that a plurality of groups of process level network devices are interconnected with a plurality of groups of bay level multicasting devices in a group-to-group correspondence manner through intermediate optical nodes, and all the process level network devices are connected with bay level semi-broadcasting or full-broadcasting devices; the intermediate optical nodes include optical access nodes and optical distribution nodes, wherein the optical access nodes are optical nodes on the process level side, and the optical distribution nodes are optical nodes on the bay level side; each group formed through the group-to-group correspondence interconnection includes at least two of the process level network devices and at least two of the bay level multicasting devices. The wave length mutual multicasting type process level optical network structure provided by the invention has the advantages that the required number of optical fibers is greatly reduced, the network structure is more orderly and simpler, the implementation is simple, and the maintenance is easy; through the wave length mutual multicasting of the intermediate optical nodes, the optical layer multicasting function and the sharing of network information on an optical layer are achieved, and the ''network sampling and network hopping'' method can be used; automatic network restructuring can be further achieved when optical cross connectors are adopted in the optical distribution nodes.