The invention discloses an optical wave and THz wave mixed guiding pohotonic crystal fiber based on the selective filling. The conventional THz functional devices are single functional devices only capable of guiding THz waves, however, optical waveguide devices are needed to be additionally introduced in the process of generating THz waves by adopting an optical method, so that the invention provides the novel optical wave and THz wave mixed guiding pohotonic crystal fiber, which can realize the mixed guiding of the optical wave and the THz wave simultaneously and further can realize an integrated THz wave functional device through adopting a material selective filling method, designing a composite structure and respectively introducing two kinds of scales, namely the optical wave length and the THz wave length to the structural parameter design. The novel composite structural optical fiber provided by the invention has the advantages that the structure is simple, the design is flexile and the performance is excellent and the like, and can effectively reduce the complexity of optical fiber design and realization.