The invention relates to a preparation method of Gandakang capsules, and belongs to the preparation method of traditional Chinese medicines. According to the invention, after a new process is determined, through study and dynamic detection of three batches of 
pilot-scale products, the character identification of the product and 
thin layer identification of four medical materials are determined, and an HPLC (high-performance liquid 
chromatography) measuring method for peoniflorin content is also built; and according to the above quality standards, the feeding process, and 
processing steps from the intermediate 
processing to finished 
product processing are effectively controlled in the improved production process of the Gandakang capsules, thus the product quality is guaranteed. The Gandakang capsules has the effects of obviously resisting aminotransferase increase caused by CCl4 and D-
galactosamine, relieving the degree of 
liver injury caused by chemical substances, and protecting liver 
cell membrane; and the Gandakang capsules also has the effects of improving 
phagocytosis function of mice and the generation of 
antibody for mouse 
hemolysin caused by sheep erythrocyte, thus the product can better improve mouse immune function, and the new 
dosage form of Gandakang capsules has good liver protection effect and has better 
treatment effect if applied clinically.