With excellent aesthetic effects and wearing comfort, bracketless invisible orthodontic treatment has become one of the important methods for the treatment of modern malocclusion and is highly recognized in orthodontic clinical practice and among patients. At present, a large number of studies have accumulated sufffcient evidence-based data regarding the indications, tooth movement efffciency, and root external resorption risk of this technology. Meanwhile, the occurrence of common oral diseases such as gingivitis, periodontitis and dental caries during orthodontic treatment is usually initiated by structural changes of oral microbiota and oral microecological imbalance, which has attracted increasing academic attention to the dynamic changes of oral microecology during orthodontic treatment. Based on relevant literature, this paper systematically reviews the variation characteristics of oral microbiota during bracketless invisible orthodontic treatment to provide references for clinical practice. Furthermore, optimization strategies are proposed based on existing research evidence, aiming to improve clinical treatment efffcacy and patient experience.