The effects of gasification pressure, coal type and oxygen/water ratio (O2/H2O) on the main gasification products (CH4, CO, CO2, H2) were studied by numerical simulation. The concentrations of CH4 and CO2 increase with the increase of gasification pressure. The concentrations of CO and H2 decrease with the increase of gasification pressure. When different types of coal are gasified at the same pressure and O2/H2O, the concentrations of CH4 and H2 in the gasification products decrease with the decrease of H element in coal, and the concentrations of CO2 and CO remains basically unchanged when the change of C content in the ultimate analysis of coal is not noticeable. With O2/H2O increases, H2 concentration decreases, while the concentrations of CH4, CO2 and CO increase first, then decrease, and there are peak values at the same O2/H2O. © Asia-Pacific Conference on Combustion, ASPACC 2019.All right reserved.