Abstract: The pomelo peel oil was prepared by cold pressing,steam distillation and mechanical microdermabrasion. The crude oil was separated into light and heavy components by molecular distillation technique,and the volatile components of crude oil and each component were analyzed by gas chromatography-mass spectrometry(GC-MS). Results showed that terpenes mainly composed of D-limonene was the most important volatile components,relative content was over 92%. The cold pressed oil had no odorous substances(limonated limonene and dextrorotatory)and better clarity and stability,so the quality of cold pressed oil was better. However,after the molecular distillation treatment,the content of terpenes in the light components of the three essential oils was over 99% and heavy components decreased. Compared with crude oil,the increment of aromatic substances content of cold pressed oil was the largest,which was contributed by heavy components. The relative content of odor ingredient(limonene)of heavy components in hot steam oil was decreased to 0.22%,it was not completely removed,however. The content of substances with retention index greater than 2000 increased to 5.92%,resulting in the decline of the clarification of essential oil. Molecular distillation technology makes more use of the comprehensive processing and utilization of cold pressed oil.