The study aims to optimize the extraction conditions of essential oil from Oregano by traditional steam distillation and simultaneous distillation-extraction. The extraction parameters were optimized by single factor and orthogonal experiments, and the essential oil was analyzed by GC/MS. The results showed that the optimal extraction process combination of steam distillation and simultaneous distillation-extraction was the basification of 1%, with extraction time for 1.5 h, solid-liquid ratio of 1:6. Under these conditions, the extraction rates of steam distillation and simultaneous distillation-extraction were 0.486 g /100 g and 0.608 g /100 g, respectively. There were 16 kinds of alkanes, 6 kinds of alkenes, 4 kinds of alcohols, 3 kinds of phenols and 1 kind of ketones in the oil obtained by conventional steam distillation, the contents of which accounted for 74.366%, 6.263%, 1.245%, 12.684% and 0.449%, respectively. 20 kinds of alkanes, 9 kinds of alkenes, 5 kinds of alcohols, 3 kinds of phenols and 1 kind of ketones were obtained by simultaneous distillation-extraction, which accounted for 60.127%, 12.597%, 2.795%, 22.147% and 0.936%, respectively. At the same time, the types and contents of main bacteriostatic components of essential oils obtained by simultaneous distillation-extraction were significantly higher than those of conventional steam distillation. The contents of thymol, cymene, γ-terpinene, carvacrol and α-hydrocene in conventional steam distillation essential oils were 8.492%, 3.286%, 2.551%, 2.143% and 0.206%, respectively. And those of simultaneous distillation-extraction were 13.925%, 5.218%, 4.509%, 4.14% and 0.36%, respectively. This study can provide reference for the production and preparation of oregano essential oil. The optimum technology obtained in this study has the high yield of essential oil, which can provide reference for the production and preparation of oregano essential oil.