Potassium channels are a widely distributed class of ion channels on the cell membrane, comprising numerous family members including voltage-gated, calcium-activated, and inward-rectifying types. These channels consist of 2 to 4 subunits with specific transmembrane domains. They are extensively distributed in cells and tissues, regulating processes such as cell membrane potential, cell signaling, and substance transport. The expression of potassium channels in tissues such as the heart, nervous system, and muscles is highly specific, and abnormalities in their function or gene mutations are closely associated with various diseases including arrhythmias, epilepsy, and myasthenia gravis.