The invention relates to a method for extracting lilac essential oil, which specifically comprises three steps of fresh flower treatment, supercritical carbon dioxide extraction, short-distance rectification and refine; the method comprises the following steps: extracting treated raw material through supercritical carbon dioxide, wherein the extracted lilac extract is faint yellow, and refining the extract by short-distance rectification technology so as to obtain lilac essential oil, wherein the lilac essential oil is golden-yellow transparent liquid; diluted lilac essential oil is pleasant and aroma; compared the lilac essential oil extracted by the supercritical carbon dioxide extraction combined with the short-distance rectification technology with the prior art, the lilac essential oil has advantages of low temperature, high efficient, no pollution and the like; the lilac essential oil extraction rate reaches to 3.5%; acquired essential oil is characterized by good quality and increased essential oil yield; and the lilac essential oil is a natural plant refining oil including curative effect and is widely used in food, medicines, health-care products and cosmetics.