Aromatic plant hydrosols are aqueous distillates generated during the process of essential oils extraction from aromatic plants through steam distillation. Unlike those of essential oils, the volatile components in the hydrosols from aromatic plants are rich in oxygenated derivatives of terpenoids such as alcohols, aldehydes, phenols and acids, which play important roles in the aroma quality and biological activities of hydrosols. In recent years, with the rampant spread of epidemic infectious diseases worldwide, research on the medicinal properties of plants has received increasing attention. Hydrosols from aromatic plants have been proven to possess a wide range of biological activities due to their unique volatile components. Research and application of hydrosols’ properties, including antibacterial, anti-inflammatory, antioxidant, antiviral, and insecticidal functions, have garnered growing interest, leading to their use and attention in the fields of food, health, and medicine.. This paper focuses on the volatile chemical components in aromatic plant hydrosols, and the research progress on their important biological activities including antioxidant, antibacterial, anti-inflammatory, and insecticidal fucntions, to provide a scientific basis for the development and utilization of aromatic plant hydrosols.