Abstract: Thymic epithelial tumors (TETs) are the most common primary tumors in the anterior mediastinum. They are characterized by a high degree of biological heterogeneity. The incidence of TETs varies geographically and is frequently associated with autoimmune diseases, such as myasthenia gravis, significantly increasing the complexity of clinical management. At present, the diagnosis and treatment of TETs are primarily based on a traditional system constructed using the Masaoka–Koga staging system and the histological classification of the World Health Organization. However, this system exhibits significant limitations in interobserver consistency, accurate prognosis assessment, and microscopic lesion detection. In recent years, the emergence of developing technologies, such as radiomics and liquid biopsy, has driven the transformation of TET diagnosis and treatment model toward precision and quantification. Radiomics enables the noninvasive risk stratification and prognosis prediction of tumors through the high-throughput extraction of CT/MRI image features, while liquid biopsy provides a new approach for dynamic monitoring at the molecular level. In terms of treatment, surgical resection remains the radical treatment for resectable TETs. Minimally invasive surgery has achieved oncology outcomes comparable with those of open surgery in resectable TETs, with better perioperative outcomes and recovery quality. For locally advanced or high-grade TETs, an individualized comprehensive treatment strategy based on a multidisciplinary team has become the core. Such strategy includes neoadjuvant/adjuvant chemoradiotherapy, targeted therapy guided by molecular typing, and immunotherapy. Future research should focus on integrating multiomics data and clinical information to further construct and optimize the precision diagnosis and treatment system for TETs.