Hedychium puerense has edible and medicinal value, and its leaves are used as a flavoring agent, but no research has been found on its essential oil components and activity. To investigate the chemical composition and bioactivity of H. puerense leaf essential oil, GC-MS was used to identify its chemical composition, filter paper diffusion method and gradient dilution method were used to determine its antibacterial activity, in vitro enzyme inhibition assay was used to evaluate its enzyme inhibition ability, and LPS-induced cell inflammation model was used to detect its anti-inflammatory effect. The results showed that 41 compounds were characterised in the H. puerense leaf essential oil, with the major components as sabinene (43.78%), β-pinene (18.94%), α-pinene (6.21%), 4-terpineol (6.00%), caryophyllene (4.90%), humulene (2.79%), and γ-terpinene (2.78%). Antibacterial assays indicated that H. puerense leaf essential oil exhibited broad-spectrum antibacterial activity against six Gram-positive and Gram-negative bacteria, with DIZ values ranging from 7.22 to 8.79 mm, MIC values ranging from 3.00 to 6.25 mg·mL-1, and MBC values ranging from 6.25 to 12.5 mg·mL-1. Enzyme inhibition assays revealed that H. puerense leaf essential oil inhibited α-glucosidase, tyrosinase, and cholinesterase, with IC50 values ranging from 11.07 to 12.5 mg·mL-1. Regarding anti-inflammatory activity, H. puerense leaf essential oil significantly inhibited the release of NO, TNF-α, and IL-6 in RAW264.7 macrophages induced by LPS within a non-cytotoxic concentration range (31.25–250 μg·mL-1). H. puerense leaf essential oil exhibits antibacterial, enzyme-inhibitory, and anti-inflammatory activities, providing a theoretical basis for its development in the food, cosmetics, and pharmaceutical industries.