The invention discloses a medicament for treating malignant tumors, and relates to the technical field of traditional Chinese medicines. The medicament is prepared by processing oldenlandia diffusa, sculellaria barbata, poria cocos, fructus arctii, achyranthes and atorvastatin calcium as raw materials according to the requirements of compatibility, and the medicament is preferably prepared into capsules and tablets. The pharmaceutical composition has certain symptom relieving, tumor shrinkage and tumor growth inhibition effects and the like on various malignant tumors such as lung cancers, liver cancers, gastric cancers, colorectal cancers, breast cancers, brain tumors and lymph cancers, can enhance the human immunity and prolong the lives of patients with tumors, and can effectively relieve adverse reactions such as leukopenia, dizziness, tireness, power leakage, emaciation, poor stomach intake and nausea and vomiting caused by the radiotherapy and chemotherapy of tumors.