Abstract: Combustions of low calorific value gas fuel in aero engine combustor were investigated experimentally,and the design of the combustor was improved.The combustion efficiency was promoted by decreasing gas velocity of primary zone and heating gas fuel.Combustor exit temperature was increased by amendments of combustor dome and fuel nozzle,and combustor temperature distribution was optimized by adding dilution tube into dilution zone of combustor.The experimental research reveals that combustion efficiency and exit temperature profiles of improved combustor are better than the prototype combustor.