Early diagnosis and treatment, along with precise therapy, are key to overcoming pancreatic and biliary tumors. As a crucial complement to traditional imaging examinations, endoscopic ultrasound plays an increasingly vital role in clinical decision-making for the diagnosis and treatment of early-stage, complex, or challenging lesions. In 2025, based on learning and summarizing the operational expertise of predecessors, mentors, and peers, the author proposed the concept of “fine linear array endoscopic ultrasound” (retrieval reference number from Shanghai Jiao Tong University School of Medicine.LIBRARY: 2026015). This paper systematically elaborates and reports on the academic philosophy and theoretical-practice framework of this concept, including its definition, significance, advantages, implementation, clinical implications, foundational requirements for learning, mastery challenges, and corresponding strategies.