Phillyrin (PHI) is one of the main active components in Forsythia suspensa (Thunb.) Vahl, belonging to the class of lignans, has anti-inflammatory, antioxidant, anti-tumor, antiviral, antibacterial, weight loss, and other pharmacological effects, involving a variety of potential signaling pathways, such as toll-like receptor (TLR), nuclear factor kappa B (NF-κB), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), nuclear factor erythroid 2-related factor 2 (Nrf2), and mechanisms related to polycyclic polyprenylated acylphloroglucinols (PPAP). The review search systematically and comprehensively CNKI, Wanfang, PubMed, Web of Science, and other databases, screened nearly 100 relevant literature in the past 5 years, and summarized and evaluated the information on PHI extraction and purification, pharmacological activity, potential mechanism, and structure-activity relationship. And further discusses the pharmacological effects of PHI and potential molecular mechanisms. The results of the review confirm that PHI has the potential to be developed into a therapeutic anti-inflammatory, anti-tumor, and other therapeutic agents, all of which provide a scientific basis and direct reference for the pharmacological research of PHI.