Gas generators are common coalgasification equipments in the industrial production.In the coalgasification process,because of some existing problems such as low calorific value and poor quality of the gas,improving the gas quality is of great importance to enlarge the application areas of the gas generator.Effects of the reaction temperature on the thermal efficiency are explained through the theoretical studies of the coal gasification process.Factors influencing the gas quality are discussed by means of the characteristic indicators of the gas generator.Technical measures on the aspects of the coal property,particle size and saturated temperature are provided.