Abstract: With soluble sugar,syringin,lobetyolin and extract contents of Codonopsis pilosula as investigation indexes,the different solid-lvquid ratio,extraction time,ethanol ratio and ultrasonic power as influencing factors,experiments were carried out by Doehlert design. A mathematical model was established based on desirability function. The optimum extraction process was determined by computer-aided calculation. Results showed that:The regression model showed a significant correlation with the experimental results,and the predicted values were close to the actual values. Through software fitting combining with practice,the optimum process conditions were obtained as follows:Solid-liquid ratio 1:60,extraction time 80 min,ethanol ratio 70%,ultrasonic power 250 W. The process validation demonstrated that the measured values was 0.91,and the deviation between the measured values and the predicted values was small. Doehlert design combined with desirability function to optimize the extraction of multiple indexes in Codonopsis pilosula was practical and feasible. Under this process,the soluble sugar was 434.14 mg/mL,syringin was 86.37 μg/mL,lobetyolin was 287.94 μg/mL,and the extract was 65.11%. The process had the advantages of high extraction rate,simple operation,simple and economical reagents.