Abstract: Coffee is rich in various bioactive substances such as caffeine, trigonelline, chlorogenic acid, polysaccharides, and flavonoids, which exhibit diverse physiological activities and potential application values. Extensive research has shown that coffee is beneficial to human health. Regular coffee consumption can prevent chronic diseases including cardiovascular disease and type 2 diabetes. Secondly, coffee consumption is also associated with a reduced risk of developing some neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and dementia. However, the underlying mechanisms of these effects are still poorly understood. This article will delve into three major categories of these substances: alkaloids, phenolic acid compounds, and terpenoid compounds. This article will expound on the health effects of the principal bioactive components in coffee from multiple angles, including immune regulation, microbiome modulation, and inflammation inhibition. This comprehensive review aims to provide a reference for the development and utilization of coffee's bioactive components, thereby contributing to the high-value utilization of coffee.