Abstract: The residual stress in polycrystalline diamond compact interface is one of important factors to evaluate the quality of its performance.Considering the effects of the thickness ratio of PDC layer and temperature fluctuations during the sintering process on the residual thermal stress of PDC, this paper analyzed the residual thermal stress of PDC by the use of a well-known finite element analysis software ANSYS.The results show that as the thickness ratio of PDC layer increases from 0.067to 0.333, the maximum radial compressive stress of PDC layer decreases from 1.61 GPa to 1.03 GPa, but the maximum axial tensile stress near the interface of PDC layer gradually increases.As the sintering temperature increases from 1000℃ to 1500℃, the maximum radial compressive stress, maximum axial tensile stress and maximum shear stress of PDC layer gradually increase.With respect to the analysis, the thickness ratio of PDC layer should be reduced under condition of ensuring the life of PDC, and the effects of raw materials and human operations on the temperature must be avoided.