The article “Teaching problem-solving in National Defense and Security Education at Tra Vinh University” focuses on the application of the Problem-Based Learning (PBL) method in teaching National Defense and Security Education (NDE). The article introduces the importance of this subject and the role of PBL in improving the quality of teaching and learning. Next, the article presents the theoretical basis of PBL, including basic concepts and benefits of this method. Related studies and theories are also mentioned to demonstrate the effectiveness of PBL in education. Finally, the article provides specific examples of the application of PBL in teaching the subject of DED, thereby evaluating the effectiveness and proposing improvements to improve the quality of teaching.