Abstract: Based on the characteristic analysis of the updraft gasifier and downdraft one, a throated twin-oxidation tar-free gasifier of coal was exploited, where tar-free gasification of coal was experimentally investigated. The effects of operational parameters on gasification performance indices were studied. The results showed that the throated twin-oxidation gasifier can reduce the tar concentration of gas and raise the heating value of gas. The tar concentration and the heating value of gas can reach 10 mg/m³ and 6466.9 kJ/m³, respectively. It entirely satisfies the various burners and heat technics' needs and makes the tar-free gasification of coal come true. Essentially, the effects of operational parameters on coal gasification performance indices are realized by changing the gasification temperature. The increase of gasification temperature can enhance the reaction rate of tar pyrolysis, thereby increasing the concentrations of CO and H2 and decreasing the concentrations of CO2 and tar of gas, and as a result, the heating value of gas increases.