To establish the three-dimensional finite element model of maxillary first premolar by using simple and effective method,which providing mathematic model for biomechanic research.Methods: Micro-CT was used to scan the extracted, intact maxillary first premolar .Collecting the point data images of enamel, dentin, and pulp by Mimics 10.0 software, which were imported into Imageware12.0 software to deal with point cloud data and inverse algorithm of curve. After surface fitting, the tooth solid model was accomplished by Ansys 11.0 software. Then, enamel, dentin, and pulp were integrated through Boolean operation in Ansys 11.0,while the solid model of periodontium and alveolar bone were constructed, and the 3D meshes were created respectively. At the same time,the model was undered loading.Result: This study established a fine three-dimensional finite element model of maxillary first premolar including pulp, periodontium and alveolar bone. After 3D meshing, the enamel had 26, 685 tetrahedral elements, the dentin had 114,082 tetrahedral elements, the pulp had 11,843 tetrahedral elements, the periodontium had 22,004 tetrahedral elements,the alveolar bone had 66,767 tetrahedral elements. In total, the model had 241,381 10-node-tetrahedral elements. The accuracy of the model was very high. It is real reflected the figure of the tooth and the curvilinear shape of enamelo-cemental junction. Conclusions: By using and combining the Micro-CT technology and reverse-engineering software, this study established a three-dimensional finite element model of maxillary first premolar. This model has favourable geometric and mechanical comparability, which imitating the stress distribution of loading.