Abstract: Dielectric barrier discharge reaction technology is an effective way to achieve the hydrogenation and upgrading of thermosensitive bio-oil under mild reaction conditions. To analyze the hydrogenation reaction pathway and mechanism of each component of bio-oil under the condition of dielectric barrier discharge, hydrogenation experiments and theoretical investigation on the simulated bio-oil prepared by model compounds were conducted based on the previous studies. The results show that butyric acid and butanol are mainly esterified to produce butyl butyrate, and the hydrogenation liquid product of hydroxyl acetone is mainly isobutyl aldehyde. Furfural is mainly saturated by hydrogenation to produce furfuryl alcohol, and the guaiacol is mainly broken by methyl to produce catechol and further hydrogenation to cyclohexene. The conversion rates of model compounds of butyric acid, butanol, furfural, hydroxyacetone, guaiacol, ethyl acetate and cyclohexane are 82.86%, 85.95%, 82.05%, 83.79%, 51.70%, 68.54% and 13.03%, respectively. Acid, aldehyde and ketone can lead bio-oil to poor corrosion and thermal stability and show high reactivity.