Abstract: Aiming at the problems of high breakage and poor process durability of CO₂ expanded cut tobacco in expansion and flouowing processings,the optimization of initial temperature of circulated airflow,flow rate and steam input in expanding process were studied with orthogonal experiment,the effects of main technological parameters on the quality of expanded tobacco were analyzed,and the qualities before and after optimization were compared.The results showed that:1)the effects of initial temperature of circulated airflow on the moisture content of expanded cut tobacco,structure and filling power of conditioned cut tobacco were the most significant,followed by flow rate and then steam input;2)the optimized parameters were initial temperature of circulated airflow 260℃,flow rate 36 m/s and steam input 2000 kg/h.The moisture content and process durability of expanded cut tobacco were raised and tobacco breakage was decreasedunder the optimized conditions.