Hydrotherapy uses water with different temperature, pressure and solute content to act on human body in different ways to prevent and treat diseases. The effects of hydrotherapy on human body mainly include temperature stimulation, mechanical stimulation and chemical stimulation. According to its usage, it can be divided into immersion bath, shower, jet bath, whirlpool bath, bubble bath and so on. According to its temperature, it can be divided into high temperature water bath, warm water bath, flat warm water bath and cold water bath; According to the drugs it contains, it can be divided into carbonic acid bath, turpentine bath, physiological saline bath and starch bath.