Case-based teaching is a teaching model that integrates theoretical knowledge with clinical practice， and it is widely used in medical education and plays an important role in standardized residency training. Taking preoperative vascular ultrasound evaluation for carotid endarterectomy （CEA） as an example， this article explores the application of the case-based teaching method in cultivating clinical thinking ability among trainees receiving standardized residency training for ultrasound. Through an analysis of typical cases， trainees engage in the whole process of clinical practice under the guidance of instructors， from medical history collection and imaging interpretation to identification of key intraoperative issues. The teaching process emphasizes the characteristics of vascular ultrasound， such as the combination of vascular structure and hemodynamics， integrated cerebrovascular and cervical assessment， and precise evaluation of collateral circulation. The case-based teaching method not only deepens the understanding of diseases among trainees， but also fosters their ability to think independently and solve clinical problems， facilitating the transition from theory to practice and ensuring precise diagnosis and treatment. This article summarizes the implementation steps and effectiveness of the case-based teaching method， in order to provide a reference for ultrasound residency training.