In order to screen out the key metabolites that control the fragrance of areca nut, enhance the fragrance of areca nut, attract more pollinators, and then increase the yield of areca nut. In this study, Headspace Solid Phase Microextraction Gas Chromatography-Mass Spectrometry Combined Analysis Technology was used for non-targeted metabolomic detection of areca nut flowers in different periods. 236 metabolites were detected in the study. 75 differential metabolites were screened by combining VIP value and differential fold. Main metabolites were terpenes, ketones, alcohols. Among them, the volatile compounds of female flowers of Areca accumulated a lot from the female flower unopened stage to the initial blooming stage, and decreased slightly in the full bloom stage, so the initial blooming stage of female flowers of Areca may be the key period for the formation of female flower fragrance. The volatile compounds in the male flowers of Areca accumulated a lot from the initial blooming stage to the blooming stage, so the blooming stage of male flowers may be the key period for the formation of flower fragrance of male flowers of Areca. KEGG database was used to analyze the metabolic pathways of differential metabolites. The fatty acid biosynthesis was the metabolic pathway that was significantly enriched in the female flowers of areca nut and related to flower aroma synthesis, and the substance enriched in this pathway was capric acid. Capric acid is a fatty acid, which is mostly used in plant physiology and signal transmission and other functions. The capric acid content in the female flowers of betel nut increased from the unopened stage to the early flowering stage, and the release of floral fragrance also increased correspondingly. This may be because areca nut starts pollination at the beginning of female flower, and more chemical signals are needed to be transmitted to attract pollinators. So capric acid may be a chemical signal released by betel nut female flowers for pollination. Metabolic pathways significantly enriched in male areca nut flowers and related to flower aroma synthesis are diterpenoid biosynthesis and fatty acid degradation. Palmitaldehyde and (4aR,6aS,9R,11aR,11bR)-4,4,11b-trimethyl-8-methylene tetrahydro-6a and 9-methylcycloheptyl [a] naphthalene were enriched in two pathways. (4aR, 6aS,9R,11aR,11bR)-4,4,11b-trimethyl-8-methylenetetrahydro-6a,9-methylcyclohept[a]naphthalene is a terpenoid. Its enantiomer, ent-kaurene, is synthesized by ring-opening of trans-geranylgeranyl pyrophosphate with the use of kaurine synthase and is a precursor ofgibberellin. The content of this substance was down-regulated from the early flowering period to the full bloom period of male flowers, which may be due to the decrease of the required gibberellin content in male flowers during the full bloom period. Palmitaldehyde is an aldehyde substance, which is a metabolite released by the biodegradation of fatty acids. The release of the fragrance of areca nut male flowers increased from the early blooming stage to the blooming stage, and the content of palmitaldehyde also increased. There is a positive correlation between these two situations. In conclusion, the above three metabolites may be the key metabolites that affect the fragrance of areca nut.