p21-activated protein kinase (PAK) is a highly conserved serine/threonine protein family that functions as an effector protein of the Rho family of small GTPases, playing crucial roles in multiple signaling pathways. Among the PAK family members, PAK4 stands out as the most representative, regulating cytoskeletal reorganization, cell proliferation, and cell cycle progression through the phosphorylation of downstream substrates. PAK4 overexpression has been observed in a variety of tumors, including pancreatic cancer, gastric cancer, and ovarian cancer, implicating its involvement in pivotal processes such as tumorigenesis and metastasis. Investigating the structure and mechanism of PAK4 is of significant value in unraveling the regulation of the cell cycle and tumor biological behavior. This article elucidates and summarizes the structural characteristics, activation process, and biological roles of PAK4 in cytoskeletal dynamics and cell cycle progression. Additionally, it reviews the latest advancements in understanding PAK4 regulation in the initiation and development of gynecological tumors, as well as research progress in PAK4 inhibitors.