Abstract: The effect of ethanol addition on the combustion characteristics of hydrogen methane mixed fuel was studied. Based on the constant volume combustion system, The laminar combustion and explosion characteristics of the three-component fuel were studied at the initial temperature of 400K, different ethanol contents (20%, 50% and 80%), different pressures (1bar, 3bar and 4bar) and different equivalent ratios (φ=0.7-1.4). The results show that under all experimental conditions, the hydrodynamic instability is most obvious when the equivalent ratio is 1.1, which is positively correlated with pressure and ethanol concentration. The laminar combustion velocity of the pre-mixed fuel is linearly affected by the initial pressure and the concentration of ethanol. The fitting correlation is in good agreement with the experimental values, and the deviation is less than 7%. The kinetic analysis shows that R1 pair is the main element reaction to increase the flame velocity of laminar flow. The linear relationship between explosion characteristics and initial pressure was obtained. The relationship between linear correlation slope, intercept and equivalent ratio was accurately determined by polynomial fitting, and the quantitative relationship between explosion characteristics, equivalent ratio, initial pressure and ethanol concentration was obtained.