Abstract: In order to investigate the characters of plasma aided coal gasification in the industry-scale equipment, the tests with changing feeding rate, steam output pressure, feeding gas (air ) flux, input power of plasma generator and the addictives (CaO and CaCO3) were carried out with Datong coal. The produced gas components were analyzed by gas chromatography. And the optimal process conditions, such as, the feeding rate of 150 g/min, the feeding gas (air or oxygen) flow of 18 m3/h, the output power of plasma generator of 100 kW, the steam output pressure of 0.3MPa are obtained. When the contents of CaO and CaCO3 in the whole feed are 10% and 5% respectively，the experimental data show their catalytic effect is the best. Considering the molar mass of CaO and CaCO3, it is concluded that the catalytic effect of CaO is more important than the reduction of CO2 in the gasification.