Abstract: Nuclear terrorism has the characteristics of strong concealment, great harm, wide range and complex composition. Once it happens, it will cause serious casualties, property losses and social panic. How to prevent nuclear terrorism has become one of the focuses of nuclear security work in various countries. In view of the slow speed of nuclide identification in the process of nuclear security, such as important traffic gates and international major events, through the overall optimization design of the system, the research of nuclear electronics and intelligent nuclide identification algorithm, this paper develops the advanced nuclear electronics module through the overall optimization design of the system, and innovatively designs the competitive weighted algorithm for intelligent nuclide identification. We have successfully developed a miniaturized, low-power portable CdZnTe(CZT) spectrometer. When the test index is 0.5 μSv/h higher than the background, the identification time of single nuclide ¹³⁷Cs is within 2 seconds, and that of mixed nuclides (²⁴¹Am, ¹³⁷Cs, ⁶⁰Co, ¹³³Ba, ¹⁵²Eu) is within 9 seconds. It can provide intelligent and fast detection technology for nuclear security department to effectively control nuclear terrorists.