Objiect:To generate three-dimension finite element mode of the first maxillary molar residual root restored with post-core crown,to analyse the stress of post-core crown of posterion tooth.Methods:Models were generate by CT scan,Mimics software and Abaqus software. Result:The three-dimensional models of the first maxillary molar residual root restored with post-core crown were generated. Conclusion:The generated three-dimensional models of the first maxillary molar residual root restored with post-core crown.were highly similar in geometry and mechanics to the real instance,which could be used to study stress of posterion tooth residual root restored with post-core crown