Direct current is a constant direction current, which can change the ion distribution in the body and adjust the body function, and is often used for drug iontophoresis; Medium and low frequency current stimulates neuromuscular contraction, reduces pain threshold and relieves adhesion, which is often used for neuromuscular diseases such as injury and inflammation. High-frequency electricity can promote circulation, eliminate inflammation and edema, stimulate tissue regeneration and relieve pain with its thermal and external thermal effects on human body. It is often used to treat injury and inflammatory pain syndrome, and high-power high-frequency electricity can be used to heat and treat cancer. The main function of static electricity is to regulate the central nervous system and plant functions, and it is often used for neurosis, early hypertension and climacteric syndrome.