Abstract: The complexity of coal constituent and the variety of downstream processes lead to variety of coal gasification technologies. Domestic coal gasification technologies nowadays were analyzed in this paper based on the coal gasification principle. It is thought that the slag flow bed is the main development direction of coal gasification technology, which possesses the advantages of high gasification reaction efficiency, high carbon conversion rate and is the best green process. The pyrolysis layer in moving bed leads to higher methane content in product gas and is good for coal to manufacture nature gas, but the problems of lower gasification intensity and alkali metals enrichment in the bed occur；Fluidized bed pyrolysis-gasification process can also raise methane content in its product gas. The gasification intensity is higher than that of moving bed if reasonable particulate size of feed coal is used. There are various problems for the other gasification technologies and need to continue to research and development or think carefully about industrial application.