Abstract: Objective: To investigate the displacement trend of maxillary first molar and the stress of periodontal tissue when the invisible appliance was moved 0.2 mm away from the maxillary first molar. Methods: Cone-beam CT (CBCT) was used to scan volunteers' maxillofacial oral conditions. Mimics 20.0 software was introduced to process the CBCT data. Geometric and physical modeling was performed using Geomagic Studio 2014 reverse engineering software and NX1911software.The model of maxilla-upper dentition-periodontal membrane-mucoperiosteal-invisible appliance was established. The 3d finite element software Ansys Workbench 2019 was used to move the model of invisible appliance to the maxillary first molar by 0.2 mm. The displacement trend, stress size and stress distribution of periodontal membrane of maxillary first molar were discussed. Results: The single displacement of the distal maxillary first molars with the invisible appliance was small, and the teeth tended to move as a whole. The maximum equivalent stress of periodontal membrane was 0.039 MPa when the invisible appliance was moved to the maxillary first molar, and the stress was mainly distributed in the buccal side. Conclusions: invisible appliances have good value for the first molar of the upper jaw that is moved far away, the force is relatively uniform, and the teeth are partial to the overall movement.