Abstract: The optimum gasification process of lignite coal in Liupanshui of Guizhou, was studied using activated carbon as the auxiliary heating medium and steam as the gasification agent. Under the auxiliary heating of activated carbon, the gasification ratio of lignite coal increased significantly and the purity of coal gas was higher. The effects of the total amount of lignite coal and activated carbon, the flow rate of gasification agent, the gasification reaction time and the microwave power on energy consumption were investigated by single factor experiment and orthogonal experiment. The results showed that under the conditions of lignite coal and activated carbon (mass ratio 1:3) of 8.0 g, gasification flux of 34.54 g/h, microwave power of 540 W and gasification time of 20 s, the lignite coal gasification ratio was 90.5 %, and the energy consumption of microwave was only 5966.8508 J/g. The composition of H2, CO and CH4 in gas is 87.32 %, and activated carbon has good effect.