Abstract: Fibroblast activation protein (FAP) is a type Ⅱ membrane-bound glycoprotein that is overexpressed in fibroblasts of 90% epithelial tumors, wound healing or inflammatory sites, but is low or absent in normal tissues, and is an important target for disease diagnosis and treatment. ⁶⁸Ga-FAPI-04 is a PET diagnostic drug based on quinoline-based FAP inhibitors, which has shown high specificity and affinity for FAP in patients both in vivo and in vitro, and has received wide attention in basic research and clinical applications. The author reviewed the basic overview of ⁶⁸Ga-FAPI-04 and its application in various malignant and non-cancerous diseases.