基于惠更斯菲涅耳衍射原理，以及相干与偏振的统一理论，研究了矢量随机电磁光束经圆环的衍射特性。研究表明在衍射场，随机电磁光束的光强分布、相干度以及偏振度分布都与圆环的拦截比以及光束的起始相干度有关。经衍射后随机电磁光束的光强分布出现奇特的链式分布，且链环存在逐级放大。入射光束起始相干度在x向与y向相等时，衍射光束的相干度和偏振度与入射光束是一样的，在衍射场光束的相干度和偏振度均匀分布。而当入射光束起始相干度在x向与y向不等时，衍射光束的相干度和偏振度与光强一样，在衍射场光轴上存在振荡，对比光强、相干度以及偏振度在衍射场光轴上的分布发现，在衍射场衍射光束光强分布为极大值时，相干度与偏振度反而为极小值。

Based on the Huygens-Fresnel principle and the unified theories of coherence and polarization of partailly coherent beams, the diffraction properties of vector random electromagnetic beam transmitted through the ring aperture has been investigated. It is found that the intensity distribution, the degree of coherence and the degree of polarization of diffracted beams are related to the interception ratio of circular ring and initial coherence. The intensity distribution of vector random electromagnetic beam is chain structure by diffraction, and the chain structure gradually enlarges. If initial coherences of the incident beam in the x direction and y direction are equal, the degrees of coherence and polarization of the diffracted beam are same as intensity of light. On the other hand in the optical axis of the diffracted beams intensity distribution, degrees of the coherence and polarization exist oscillation. Moreover, when the intensity is maximum in optical axis of the diffracted beams, the degrees of coherence and polarization is minimal, and vice versa.