Security black technologies were thrust to the spotlight at the 4th "Lianyungang Security Expo" that opened Wednesday. Various intelligent security devices are dazzling to the eyes. This millimeter-wave human body security detector, based on AI intelligent deep learning, can quickly identify drugs, explosives, firearms, ceramic knives and other items in just two seconds and automatically sound alarm. An unmanned security boat attracted the attention of many visitors. Nearly 300 leading security companies at home and abroad participated in the exhibition. The products displayed at the exhibition site, including network security and police equipment, are the latest achievements in the industry, demonstrating the achievements of high-tech assistance in the development of actual police services.