Based on the research on the structures of two types of photonic crystal functional devices,optical beam splitters,and filters,this paper designs a novel two-dimensional triangular lattice photonic crystal filtering beam splitter,which can simultaneously achieve power beam splitting and filtering functions.The finite difference time domain method are used to analyze the transmission characteristics of light waves in the new structure.The results show that the proposed structure successfully integrates the characteristics of filtering and beam splitting,and can simultaneously achieve good filtering and beam splitting functions under different incident wavelengths.For a wavelength of 1.527 μm and 1.550 μm,the incident light wave is basically symmetrically split and output,with transmittance of 66.77% and 95.22%,respectively.Meanwhile,for the incident light waves of these two wavelengths,the structure also has good filtering performance,with corresponding filtering efficiencies of 70.62% and 92.76%,respectively.In addition,for a wavelength of 1.577 μm,the structure mainly functions as a filter,with a filtering efficiency of 98.11%.