[Objective] To optimize the supercritical CO2 extraction processes of free anthraquinones from Rheum palmatum L.,so as to provide reference for the exploration of new extraction process for traditional Chinese medicine.[Method]The extraction conditions were optimized with the orthogonal test based on single factor test.[Result]The optimum extraction conditions were as follows: static extraction duration of 30 min,dynamic extraction duration of 15 min,absolute ethanol dosage of 2.0 ml,extraction temperature ...