Abstract: As a critical means of preventing illicit nuclear material trafficking and nuclear terrorism, nuclear security detection technology has undergone a leapfrog development from traditional radiation monitoring to intelligent multimodal detection. The current technological system, centered on dual-energy X-ray imaging, neutron element analysis, forms a comprehensive protection network covering material identification, behavior monitoring, and data security. This article provides a comprehensive review of the application and development of nuclear detection technology at the China Institute of Atomic Energy in the field of nuclear security. It first elaborates on the developmental trajectory of nuclear detection technology, with a focus on innovative applications by the China Institute of Atomic Energy in nuclear security. It then analyzes the current state of technological advancement and the challenges faced, and finally prospects future trends in intelligence, high sensitivity, and multimodal integration, emphasizing the pivotal role of nuclear detection technology in advancing nuclear security.