Three major gynecological malignancies (ovarian cancer, endometrial cancer, and cervical cancer) severely affect women’s life and health. The development and progression of tumors are complex and closely related to the tumor microenvironment. Cancer-associated fibroblast (CAF) is an important part of the tumor microenvironment, having the ability to secrete a variety of cytokines and synthesize cell-matrix proteins. Fibroblast activation protein (FAP) is one of the most potential molecular markers of CAF, can promote the proliferation, migration, and invasion of tumor cells, remodel the extracellular matrix, and induce tumor neovascularization. It is an indispensable factor in tumorigenesis. The research of FAP (as a tumor diagnostic tracer and a targeted drug) has made some progress, which provides a new direction for the diagnosis and treatment of gynecological malignancies.