MicroRNAs (miRNAs), a large class of short non-coding RNAs, can directly bind to the 3′ untranslated region of target genes, thus affecting gene expression and playing a key role in cardiovascular diseases. Among them, miRNA-206 (miR-206) is a key regulator of heart development and physiological activities, and can not only be used as a marker molecule for diagnosis, but also as a targeted action point for disease treatment. This paper reviews the basic functions of miR-206 in regulating cardiomyocytes, endothelial cells, smooth muscle cells, autonomic nerve cells and other cells, as well as the specific roles and mechanisms of miR-206 in the occurrence and development of coronary artery disease, myocardial infarction, heart failure, arrhythmia, pulmonary hypertension and other diseases.