To provide basic data for the development of industrial circulating fluidized bed (CFB) synthetic waste gasification technology,the effect of excess air coefficient and O volume fraction on the gasification characteristics of synthetic waste were studied in a pilot-scaleCFB gasifier. The synthetic waste used in the experiment is a material made of single-component waste,which consists of paper,fabric,sawdust,ash and water,respectively,according to the mass fraction of 60%,10%,10%,10% and 10%. The problem of poor feeding ofblock material in the pilot test was solved by using synthetic waste and boiler bottom slag alternately. The gasification temperature increased from 850 ℃ to 950 ℃ when the excess air coefficient increased from 0.31 to 0.50. The calorific value of the generated gas is3 976-2 590 kJ/ m. CO yields increases,H yields increases first and then decreases,and CH yields decreases.The gas production rate is2.28-3.08 m / kg,the cold gas efficiency is 42.97%-51.01%,and the carbon conversion rate is 83.11%-92.45%. As O concentration increased from 30% to 50% at around 900 ℃ ,the water-gas shift reaction was enhanced. The overall yields of CO、H and CH improvesand calorific value of the generated gas improves (5 274-7 294 kJ/ m). The gas production rate is 1.37-1.93 m / kg,the carbon conversion rate is 83.32%-81.11%,and th e cold gas efficiency is 55.39%-53.77%.The steady operation of synthetic waste gasification is realized in a pilot-scale CFB gasifier for 108 hours. The temperature at the bottom of gasifier is relatively low and the temperature distributionfrom the bottom of gasifier to the top is relatively uniform. The temperature difference within 19.7 ℃ indicates that stable material circulation inside the pilot-scale CFB.