Objective To investigate the displacement trend and periodontal stress distribution of the mandibular second molar under different force values and reinforcement methods by three-dimensional finite element method, so as to provide reference for clinical practice. Methods In May 2023, conical beam CBCT data of a patient in the Department of Dental Imaging of the First Affiliated Hospital of Xinjiang Medical University were selected to establish a 3D finite element model of the missing first molar. Different corrective devices were placed on the crown of the second grinding tooth, and the groups were divided by different force values (100 g or 50 g) and additional force methods (mesial traction hook or distal traction hook), a total of 8 working groups. Abaqus software was used to simulate and compare the displacement trend and the stress distribution of periodontal membrane of the second molar in 8 working conditions. Results The maximum Von Mises stress of the periodontal membrane did not exceed 2.6×10-2Mpa in all conditions, and the stress distribution of the distal traction hook was more uniform than that of the proximal traction hook. When the buccal Stress was 50 g and the lingual stress was 100 g, mesial translation occurred on the buccal side of the second molar, buccal rotation occurred on the mesial side, and the maxillary side rotated to the mesial side, which was basically consistent with the results of the apical group. At this time, the Maximum Principal Stress distribution of the periodontal membrane was mainly concentrated on the distal side of the second molar periodontal membrane. Conclusion ①The stress distribution of the distal traction hook is more uniform when the mandibular second molar is moved mesially; ②When the traction hook is applied 100 g and the lingual buckle is applied 50 g, the second molar appears a trend of distantly rotating movement from the buccal side, which can provide clinical reference for correcting the tilted second molar; ③Under the condition that the buccal force of the distal traction hook is 50 g and the lingual force is 100 g, the second molar is the closest to the overall mesial movement trend, and the stress distribution is uniform.