Abstract: In order to effectively improve the quality of combustible gas in the high temperature coal gas of converter and reduce the content of CO2 ,in this paper,a method for preparing high-quality gas by injecting coal powder into high temperature coal gas of converter was presented. In this test method,FactSage 6. 1 was used to calculate the possi- bility of reaction between components,and the pyrolysis,gasification and catalytic gasification behavior of coal char were analyzed by thermogravimetric analyzer. The dynamic precipitation characteristics of gas products from 900 ℃ to 1 200 ℃ were studied by means of settling furnace experiments,and α,β were calcu-lated as evaluation indexes,which were further verified by industrial tests. The test results show that the loss of coal char mass is due to the gasification behavior of CO2 ,the initial temperature of gasification reaction decreased by 62 ℃ ,the temperature at the end of gasi- fication reaction decreased by 117 ℃ ,the contents of H2 and CO in coal gas increased significantly,and the contents of CO2 and CH4 decreased significantly. Without additives,the α value increased from 7. 63% at 900 ℃ to 17． 27% at 1 200 ℃ ,and the β value increased from 4. 42% at 900 ℃ to 27. 52% at 1 200 ℃ . With additives,the α value in- creased from 11. 51% at 900 ℃ to 37. 64% at 1 200 ℃ ,and the β value increased from 11. 48% at 900 ℃ to 54． 72% at 1 200 ℃ . In the range of 900 ℃ to 1 200 ℃ ,the α value increased with the increase of temperature,and the β value decreased with the increase of temperature. At 1 200 ℃ ,compared with those without additive,the value of α increased 20. 37% ,β decreased 27. 20% ,This is because the additive catalyzes the gasification of coal powder. Compared with the experimental results of the settling furnace,the α and β values obtained by the industry increased by 5． 29% and 4. 96% ,respectively,and the industrial test value was slightly larger than the experimental value of the settling furnace. The feasibility of the method of preparing high-quality gas by blowing coal powder into high-tempera- ture gas of converter was verified by the test results. The design and application of the test method can provide a refer- ence for the quality optimization of combustible gases in the high temperature coal gas of converter.