The invention relates to a medical composition for treating liver disease (that is shu gan shun Qi medical composition) and a preparation method thereof. The medical composition is prepared from 13 crude drugs including Magnolia officinalis, Rhizoma Chuanxiong, Nutgrass Galingale Rhizome, White Peony Root, Chinese Thorowax Root, Fructus Aurantii Immaturus, Aiomatic Turmeric Root-tuber, Fructus Citri Sarcodactylis, Radix Aucklangiae, dried orange peel, licorice, Rhizoma Corydalis Yanhusuo, Kalimeris indica; the basic preparation method comprises the following steps: grinding the raw medicines into fine powder, uniformly mixing the powder, then adding pharmaceutical excipients for uniform mixing, and drying the mixture to obtain the formulation needed. Partial medicinal materials in the composition contain volatile substances, so the invention adopts the steps of firstly crushing 2/3 of the raw materials, and then crushing the remaining 1/3 of the crude drugs, performing reflux extraction and then decocting to fully utilize effective ingredients, the medicine can be absorbed completely and the medicine efficiency is enhanced. The raw material ratio is screened in a scientific way, and the composition has the effect of smoothing liver, regulating vital energy and alleviating pain, can be used for treating liver depression and qi stagnation symptoms such as rib tumescence, stomach hurt, vomit against the noisy, and belching to realize address both the symptoms and root causes.