At present, research on purple octagonal column-shaped cultural relics unearthed in China is mainly concentrated on materials and production processes, and there are relatively fewer systematic discussions of their sources and functions. In our work, we used ultra-depth 3D video microscopy, polarized light microscopy, X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), laser Raman spectrometry and other analytical methods, to explore the surface characteristics, particle shape, material composition, production process and other information of a purple octagonal column artifact unearthed from a Qin tomb of the Warring States Period at Hejia Village of Zhouling Town. Based on our results, we discuss the possible source and evolution of the octagonal prism shape, the source of the materials, functional uses, etc. The results show that the purple octagonal prism has a microscopic morphology of purple and yellow crystal particles, and the main component is Chinese purple (copper barium silicate), which is presumed to have been fired twice to three times. Based on thorough literature review, it is speculated that the shape of the octagonal prism was greatly influenced by the native Chinese Taoist culture, and its main function is oral or congested. This work represents a significant reference for the systematic study of purple octagonal prisms unearthed in China.