基于光波在直波导和复合结构光子晶体中的传播特性,结合平面波展开法和时域有限差分法,提出并讨论了一种新型的超紧凑的光子晶体偏振光分束器.它是由输入波导,分束结构和输出波导三部分组成.对这种结构的三角晶格光子晶体光分束器的数值计算与模拟结果表明,该结构可以实现TE模和TM模的高效大角度分离,并且在通信波段设计尺寸小,这些特性使其在未来的集成光回路中有着重要的应用前景. Based on the propagation characteristics of light waves in straight waveguide and composite photonic crystals, a novel ultra-compact photonic crystal polarization beam splitter is proposed and discussed based on the plane wave expansion method and the finite-difference time-domain method. It consists of an input waveguide , The beam splitting structure and the output waveguide.The numerical calculation and simulation results of the triangular lattice photonic crystal beam splitter with this kind of structure show that the structure can realize high efficiency and large angle separation of the TE mode and the TM mode, The small design size of the communications band makes these features an important application prospect in the future of integrated optical circuits.