Maybe shooting on TV is a sense of technology, but it's not so magical. The spy warfare technology in the Song Dynasty was relatively developed, but after all, the technology was underdeveloped at that time, so there should be no sense of science and technology. Spies existed in ancient times, and many ancient people made certain contributions to the country as spies. At that time, most spy techniques were not very developed. In the Song Dynasty, spy technology reached a peak.

There are two kinds of spy agencies in Song Dynasty, one is the central spy and the other is the folk spy. Some central spies are responsible for preventing foreign spies from doing anything harmful to their own countries, and some diplomats in their own countries are responsible for leaking state secrets. There are also many local spies, some of whom are trained by the border guards themselves. They sent spies to other countries, causing them to disrupt the politics of other countries and bring benefits to their own countries.

Different spies do different jobs, their purpose is to get information, and finally they will pass the information they get to their own country. We all know the story of Zhou Youwang's war drama The Prince. In fact, this is a way to transmit information, but this way can only transmit some simple information, and we have to use post to transmit complex information.

Spy technology in Song Dynasty was very good, because it was very dangerous for information to fall into enemy's hands, so it was very important. Spy techniques in Song Dynasty included wax pills, alum books and secret words. None of these were produced in the Song Dynasty. The typical spy technique in Song Dynasty was word checking, that is, using passwords to transmit information.