In the research field of photonic crystal (PC) devices,there is a lack of research on multifunctional devices.This article proposes a two-dimensional square lattice photonic crystal wave guide structure of beaming of light emitting with filtering function.The output port of this structure is in a stepped horn shape,through the interference between the radiation wave and the surface wave generated by the contact horn surface,the light beaming is enhanced,and the effective propagation distance is greatly increased.In addition,there are two coupled filters at the front end of the horn opening,respectively filtering the center wavelength of 1.505 μm and 1.516 μm narrow band,filtering efficiency reaching 99.64% and 99.02%.Through the structural design of the above two parts,when the wavelength of the incident light is not in the narrow band range of 1.505 μm and 1.516 μm,the induced beaming of light emitting will be greatly enhanced.According to the finite-difference time-domain analysis,the effective propagation distance of the structure reaches 111.4 μm when the input wavelength is 1.460 μm.