Terahertz is very heavy. For THz imaging technology, the equipment required is usually larger and heavier because it requires the use of high-power THz lasers and high-sensitivity detectors. In this case, heavier equipment usually has better mechanical stability and thermal stability. The imaging quality can be better guaranteed. The terahertz band refers to the electromagnetic wave frequency range between 100GHz and 10THz. It is also called submillimeter wave or submillimeter wave. THz wave has the characteristics of strong penetrating power and harmlessness. It is widely used in medicine, security inspection, materials science and so on. It is widely used in other fields. Therefore, the requirements for THz devices are also different for different application scenarios.