Abstract: Aiming at the refractory characteristics of alkali lignin, the study on the gasification of alkali lignin in supercritical water was carried out in a batch reactor with Ru/C nanotubes as the catalyst. The effect of temperature, water density, time, concentration of the reactant, catalyst amount on the gasification of alkali lignin was discussed, as well as the catalytic efficiency of the Ru/C catalyst nanotubes. The optimum conditions of the catalytic gasification of alkali lignin on the Ru/C nanotubes obtained with single factor analysis were the reaction temperature of 600 ℃, 0.128 4 g/cm³ water density, 60 min reaction time, 3.0% reactant concentration, catalyst amount of 0.5 g/g (alkali lignin). The results show that during the gasification process of alkali lignin in supercritical water, the high temperature, high water density (or pressure), long reaction time, low reactant concentration and right amount of catalyst will be in favor of the gasification reaction. The alkali lignin gasification efficiency and carbon gasification efficiency reached 73.74% and 56.34% under the optimal reaction conditions, and the hydrogen production capacity was also significantly improved.