In consideration of the advantage of micro X-ray diffraction (micro-XRD) technology, such as micro area, trace, in situ, undamaged and so on, the author attempts to use this technology combined with the super depth of field microscopy, scanning electron microscopy, energy spectrum analysis (SEM-EDX) and micro laser raman spectroscopy(MLRM) for the first time in this paper, to observe microscopic, nondestructive analyse and identify the violet pigment sample unearthed in the site of eastern gate tower of Han Yang mausoleum. The results confirm that the composition of this violet pigment is Chinese Purple (BaCuSi2O6), accompanied by lanarkite (Pb2［SO4］O) and barite (BaSO4). Chinese Purple like type of copper barium silicate pigment was found in the ruins of western han dynasty mausoleum, which reflects that the purple colour has a high social status level at that time. And it appeared in the eastern gate tower shows that the design and decoration of western han dynasty emperor’s mausoleum in terms of the influence of theory of Five Elements. Furthermore, the discovery of lanarkite and barite makes the author to speculate that barite is Barium raw material, and lanarkite plays the part of fluxing agent and catalyst as lead additives in the process of synthesis Chinese Purple. And then it further reflects that the synthetic technology is mature enough from the perspective of the history of chemistry at that time.