The invention relates to a drug composition. The drug composition consists of an effective treating amount of calcium antagonist (CCB), an angiotensin II receptor blocker (ARB), a thiazide diuretic, a folic acid compound and a pharmaceutically acceptable carrier, wherein the content of the CCB is 2-240 mg, the content of the ARB is 4-600 mg, the content of the thiazide diuretic is 0.625-25 mg, and the content of the folic acid compound is 0.4-0.4 mg. The drug composition has the advantages that the drug composition can effectively improve the treatment effect of reducing blood pressure of class-2 and class-3 hypertensive patients, strengthen the effect of protecting target organs of the patients and reduce the occurrence risk of cerebral apoplexy complications caused by high blood pressure. In addition, the drug composition can be conveniently taken by patients, the treatment compliance is greatly improved, and the medical costs can be also reduced.