Abstract: Science and technology security is an important part of China's national security system, and science and technology elements play a key role in supporting and ensuring national security. From the perspective of national security, this paper analyzes the evolution and connotation characteristics of the concept of science and technology security, analyzes and puts forward the judgment criteria and internal logic of science and technology security issues, and uses the case of " Neck Sticking" problem to prove it. On this basis, this paper uses the method of system element analysis to study and construct the science and technology security system in the New Era. The results show that the science and technology security system consists of four main components, including the subsystem of science and technology security components, the subsystem of science and technology security output, the subsystem of science and technology security environment and the subsystem of science and technology security governance, which together constitute the national science and technology security system.