Abstract: Atrial fibrillation (AF) is a common arrhythmia with high incidence rate and mortality. At present, significant progress has been made in its treatment, and there is still much room for improvement in its specific treatment plan. The key to treatment is to discover the underlying key basic mechanism. Research shows that trimethylamine N-oxide (TMAO), a metabolite of intestinal flora, plays an important role in cardiovascular diseases such as arrhythmia, and can be used as a prognostic biomarker. TMAO is associated with the occurrence, progression, recurrence and risk of embolism of atrial fibrillation (AF). In this paper, we first reviewed the basic electrophysiological mechanisms related to the clinical features of AF, and the potential mechanisms of TAMO in the pathogenesis of AF. At the same time, we discussed that TMAO and related signal pathways may become potential therapeutic targets of AF. In addition, for AF patients with high TMAO, the significance of individualized interventions in the future was prospected.