Thermal therapy instrument is to heat the human body tissue to achieve clinical efficacy of the instrument, mainly microwave therapy instrument, infrared therapy instrument, short-wave therapy instrument and ultra-short-wave therapy instrument and other common equipment. The main mechanism of these devices is the use of electromagnetic waves can produce thermal effects, so that the temperature of human tissue rises to expand blood vessels, improve blood circulation, promote the absorption of inflammation and improve the nutritional relationship between cells and metabolism, compared with the infrared penetration is the weakest, the treatment of the need for bare human tissue. Short-wave, ultra-short-wave penetration is the strongest, but the fat of such electromagnetic wave absorption is too strong, the power is too high easily lead to fat liquefaction. Among them, the thermal effect of microwave therapy device is the most significant, so the efficacy is also recognized by the medical institutions.