The coal gasification experiment and thermodynamic calculation of the newly developed moving bcd coal gasifier with a draft tube are done according to the thermodynamic calculating model built on the basis of chemical reaction equilibrium, mass balance and heat balance. The obtained experimental results are quite approaching to the thermodynamically calculated values. The effects of steam/coal ratio, air/coal ratio, reaction temperature, reaction pressure, steam temperature, air temperature on the thermodynamic indexes of the gasifier are examined through thermodynamic simulating calculations. Under the optimal simulating conditions, gas calorific value, cold gas thermodynamic efficiency and available energy efficiency can reach 12 MJ/Nm(3), 88.6% and 95.4% respectively, when air is used as the oxidizer. Compared with the directly-burning-coal-gasifier, the gasifier exhibits good characteristics and prospects for industrial application.