With the depletion of fossil fuels and the emergence of biofuels, ethanol-hydrogen fuel as a new generation of clean renewable fuel has attracted widespread attention. It is necessary to study the effects of ethanol-hydrogen air premixed flame combustion characteristics. Based on the constant volume combustion system, the laminar combustion characteristics of ethanol/hydrogen/air premixed flame were studied under the conditions of initial temperature of${400}\mathrm{\;K}$, hydrogen ratio of${20}\%$, equivalent ratio of${0.7}\sim {1.4}$and initial pressure of$2 \times {10}^{5},3 \times {10}^{5}$and$4 \times {10}^{5}\mathrm{\;{Pa}}$. Based on the mechanism of ethanol oxidation of Marinov and experimental data, the laminar combustion rate of Marinov was studied and the influencing factors were analyzed. Based on Chemkin-Pro software, the chemical reaction kinetics and numerical study were carried out. The results show that the laminar combustion rate of mixed fuel slows down with the increase of pressure.$\mathrm{H}$group is the main pathway of ethanol consumption, and$\mathrm{H},\mathrm{O}$, and$\mathrm{{OH}}$radicals play a leading role in the reaction of${\mathrm{{SC}}}_{2}{\mathrm{H}}_{4}\mathrm{{OH}}$and${\mathrm{{PC}}}_{2}{\mathrm{H}}_{4}\mathrm{{OH}}$from$\mathrm{H}$extracted by ethanol.$\mathrm{R}1 :\mathrm{H}+ {\mathrm{O}}_{2}\rightleftharpoons \mathrm{O}+ \mathrm{{OH}}$has the most positive effect on laminar combustion speed. The peak molar fraction of the active radical pool composed of active free radicals(H, OandOH) has a good correlation with the laminar combustion rate of ethanol in the whole equivalent ratio range, and the influence is huge. Further exploring this correlation, it is found that there is an approximate linear relationship, and the expression of laminar combustion rate with the peak molar fraction of$\mathrm{H}+ \mathrm{{OH}}+{\mathrm{{CH}}}_{3}$and$\mathrm{H}+\mathrm{{OH}}$is fitted.