The invention discloses a pharmaceutical composition for treating intermediate and advanced malignant tumors and a preparation method thereof. The composition mainly comprises the following raw material medicines: tuckahoe, dried orange peel, immature bitter orange, red peony root, rhizoma sparganii, rhizoma zedoariae, tangkuei tail, safflower, spina gleditsiae, peach kernel, medicated leaven, giant knotweed, Tonkin sophora root, radix rehmanniae, madder, radix sophorae flavescentis, radix stephaniae tetrandrae, chinaberry fruit, dried ginger, radix saposhnikoviae, radix bupleuri, lithospermum, magnolia officinalis, trichosanthes root, raw gypsum, rhizoma anemarrhenae, radix scutellariae, goldthread, cyperus tuber and radix linderae. The pharmaceutical composition of the invention can be prepared into any oral preparation by using the common preparation method of traditional Chinese medicines. The pharmaceutical composition of the invention can improve many malignant physical symptomsof patients suffering from intermediate and advanced malignant tumors and especially patients losing the chance of operations, radiotherapy and chemotherapy, can reduce the tumor volume after being taken for a long time, and has little toxic side effect and relatively low cost.