The weight of each quality index of the expanded tobacco was determined by the analytic hierarchy process, and the comprehensive quality score was obtained by the comprehensive evaluation after the data standardization. On the basis of single factor test, the main factors, such as cold end immersion time, hot end process gas temperature, hot air speed and steam application amount, were selected to study their influence on the comprehensive quality score. Finally, the response surface method was used to optimize the processing conditions of expanded tobacco. After optimization, the process conditions are as follows: Soaking time 42 s, process gas temperature 291 ℃, wind speed 38 m/s, steam application 500 kg/h, and the comprehensive quality score is 1.052.