The lamellar exfoliation of the glaze layer and efflorescence of the matrix of green glazed tiles from a representative parapet sited in the Museum of the Former German Governor’s House in Qingdao, were studied using scanning electron microscopy-energy dispersive spectrometry, micro-zone X-ray diffraction, thermal diffusion coefficient analysis, thermal expansion property analysis and interface tension analysis. The results show, first, that there were differences in thermal diffusivity, thermal expansion capacity and other interfacial properties of the protective material, glaze and matrix, which caused corrosion products containing phosphorus, lead and calcium to form at the interface between the matrix and glaze, especially at the ice crack extension area of the glaze layer; thus, decreasing the interfacial bonding strength between the matrix and glaze; the ice cracks were extended and connected to the cracks formed at the weak joints between the matrix and glaze, resulting in lamellar exfoliation of the glaze. Second, a calcium sulfate crystal zone was formed between the matrix with a protective layer and the internal interface, resulting in the increase of pores at the interface and a decrease of particle bonding strength, which was speculated to be the main factor causing the lamellar exfoliation of the unglazed matrix. This research on the internal causes of lamellar exfoliation of the glaze layer and matrix could provide a scientific basis for further conservation.