In theory, 3D printing technology has the potential risk of being used to make weapons that are not easy to detect, but in practice it is subject to a variety of restrictions and controls. On the one hand, 3D printing technology can realize the manufacture of more complex shapes of items, which may be used to manufacture some small, concealed weapon parts or improvised weapons. On the other hand, the international community and governments have many regulatory measures for the application of 3D printing technology. Many countries strictly control the import and export of related raw materials, 3D printing equipment and technology to prevent them from being illegally used in the manufacture of dangerous goods such as weapons. At the same time, law enforcement and security agencies are constantly improving their ability to detect and identify suspicious items manufactured using 3D printing technology, and prevent such risks through various methods such as technical means and intelligence analysis. Overall, although there are potential possibilities, through effective supervision and technical response, the threat posed by the use of 3D printing technology to manufacture undetectable weapons can be greatly reduced.