Abstract: To compare the differences in volatile components between white pepper essential oil extracted by ultrasound-assisted steam distillation and traditional steam distillation, the two methods were used to prepare the essential oil in this study. Subsequently, combined with LLE, the sample was comprehensively analyzed using GC×GC-O-TOF-MS. Additionally, aroma extraction dilution analysis (AEDA) was conducted to screen for aroma-active compounds with a dilution factor (FD) of ≥32 for precise quantification, and their odor activity values (OAVs) were subsequently calculated. The results indicated that a total of 109 volatile odor compounds, including 49 terpenoids, 27 alcohols, 12 ketones, 7 aldehydes, 5 esters, and 9 other compounds, were identified in the two white pepper essential oils. By comparing the types and concentrations of volatile compounds in these oils, it was observed that ultrasound-assisted hydrodistillation exhibited effective extraction of terpenoids. Olfactory analysis detected odors from 41 aroma-active compounds in the two white pepper essential oils. The OAV values of aroma-active compounds, including 3-carene, myrcene, α-terpinene, (+)-limonene, p-cymene, caryophyllene, linalool, and terpinine-4-ol, in white pepper essential oils obtained through ultrasound-assisted hydrodistillation were all increased. These findings suggested that ultrasound-assisted hydrodistillation not only improves the extraction rate of white pepper essential oil but also effectively promotes the generation or release of aroma-active compounds. This study provides a methodology and insights for enhancing the flavor quality of plant essential oils extracted by traditional hydrodistillation.