Objective To analyze the biomechanical properties of the oral and maxillofacial system of the maxillary anterior teeth in the case of periodontitis, and to provide theoretical basis and clinical guidance for the invisible orthodontic treatment of such patients. Methods Based on volunteers' maxillofacial CT data and medical/engineering software, a three-dimensional finite element analysis method was used to extract and establish a three-dimensional model of oral maxillary tissue of volunteers under invisible appliance, namely, no periodontitis (group A), mild periodontitis (group B) and moderate periodontitis (group C). In the finite element analysis results, the displacement of the left maxillary anterior teeth and the stress of the periodontal ligament were monitored in groups A, B and C, respectively. Results Under the correction load, the maxillary anterior teeth of the three groups A, B and C all produced effective displacement, that is, with the increase of periodontitis, the total displacement near the incisal end of the crown and the cusp of the canine increased first and then decreased slightly. The displacement of the root tip decreased with the increase of periodontitis, and the overall displacement difference between the crown and the root continued to increase. The stress value of periodontal ligament (stress concentration area ) near the neck of maxillary anterior teeth increased first and then decreased slightly with the degree of periodontitis, but it was still greater than that without periodontitis. Conclusion For periodontitis patients with maxillary anterior teeth retraction under invisible appliance, the overall movement of the teeth can be induced by increasing the root-lingual torque and reducing the internal retraction load, and the stress damage to the periodontium can be minimized, so as to obtain a more safe and effective invisible correction effect.