With the development of social economy and technology, microwave volume scanner has become one of the most important instruments in global security and threat detection kits. With the continuous development and progress of radio frequency, microwave and millimeter wave technology, the whole do people screening based on this technology is becoming more and more popular. This paper outlines how these microwave human are used for people screening and how they work. Hopefully, it will help you better understand the device that can be used for people screening.