Abstract: Pancreatic cancer, particularly pancreatic ductal adenocarcinoma （PDAC）, has an insidious onset and rapid progression, and early diagnosis and precision treatment remain challenging. Contrast-enhanced CT and MRI/MRCP remain the basis for staging and resectability assessment, whereas ultrasound-related technologies is primarily reflected in high-resolution local evaluation, tissue acquisition, and interventional support. Current evidence indicates that endoscopic ultrasound （EUS） and EUS-guided fine-needle biopsy （EUS-FNB） have become mature key techniques for detecting small lesions, local staging, and obtaining tissue for histopathologic and molecular analyses. EUS-guided biliary drainage and celiac plexus neurolysis have established palliative roles in selected patients with biliary obstruction or cancer-related pain. By contrast, Contrast-enhanced EUS, elastography, and artificial intelligence are primarily adjunctive tools for lesion characterization, target selection, and quality improvement, while EUS-guided radiofrequency ablation, high-intensity focused ultrasound, and local delivery remain in the exploratory stage. The main evidence gaps include patient selection, technical parameters, optimal integration with systemic therapy, and confirmation of survival benefit through multicenter randomized studies. This review summarizes the clinical positioning, key quantitative evidence, and future research priorities of ultrasound and related technologies in the diagnosis and treatment of pancreatic cancer according to the above evidence levels.