Stresses and its variation of coating and matrix are measured by XRD (X-ray diffraction). A test system that measures coating stress on the bonding interface is established, and the measurement of interface bonding status is researched. By using interfacial stress variation before and after coating debonding from matrix, combined with the physical parameters of coating material and temperatures field parameter of coating-matrix system, the bonding strength of coating-matrix is represented by the diffraction peak of coating residual stress. A new experiment method to measure bonding strength of coating and matrix is introduced which is applicable to measuring interfacial bonding strength of all kinds of polycrystalline thermal barrier coatings.