As an ancient high-class building material, glazed tiles have been used in palaces and royal temples since the Northern Wei dynasty. In the Liao and Song dynasties, glazed tiles were not only used in royal buildings, but also used in cemetery buildings. The existing glazed tile in Ming and Qing dynasties is characterized by a large numbes of glaze layers falling off. However, on this remnant of green glazed tile in liao dynasty studied in this paper, although the glaze layer is extremely thin, ice cracks are all over the surface and the surface is white, the glaze layer is completely well preserved, almost no obvious warping and falling off, and has a good strength. In this paper, the super depth of field microscopy, scanning electron microscopy and energy spectrum(SEM-EDS) and X-ray diffraction(XRD) were used to study the technology and preservation of green glazed tile fragments unearthed from Xinli site of Liao dynasty emperial mausoleum site in Yiwulu Mountain of Beizhen Town in Liaoning province. Combining with literature materials, the results show that the raw material of green glazed tile in Liao dynasty is high quality porcelain clay with a few small grains of sand. Its phases include quartz (SiO2), cristobalite low (SiO2), sillimanite (Al2［SiO4］O) and corundum (Al2O3), which is an early example of ceramic clay as body. The green glaze layer belongs to the basic PbO-SiO2-Al2O3 glaze system, which takes Cu as the color element, and the Pb content is lower than that of the glazed tiles of Ming and Ding dynasties. The lack of ZnO in the composition may be the reason why the glaze is of different shades of turquoise and low gloss. Green glaze has almost no peeling, and the bond strength of the glaze is very good, which is because the low lead thin glaze reduces the thermal expansion coefficient, eases the stress, the glaze thermal expansion coefficient matches, and shallow surface cracks are not easy to connect the internal and external environment. In addition, its use and storage environment are relatively dry, reducing the impact of water, almost no hygroscopic expansion and freezing expansion. This paper provides a reference for the study of similar cultural relic samples, the research on the construction technology of colored glaze in Liao dynasty and the preservation of colored glaze cultural relic, and promotes the related research work.