Esophageal cancer is a common malignant tumor of the digestive tract in China, and most patients are detected in advanced stage. Early diagnosis and assessment of the efficacy of esophageal cancer are key to optimizing treatment strategies and improving prognosis. Positron emission computed tomography/ computed tomography (PET/CT) is an imaging method that integrates molecular function and anatomical structure, and has shown significant value in the diagnosis and treatment of tumors. This article focuses on the application and progress of PET/CT in the diagnosis and staging of esophageal cancer, assessment of efficacy, prediction of prognosis and planning of radiotherapy.