Nifedipine is a calcium antagonist of the dihydropyridine class, which works by inhibiting the entry of calcium ions into cardiac myocytes and smooth muscle cells, as well as the transfer of calcium ions from cells, but not the plasma concentration of calcium ions, thus achieving the purpose of diastole and lowering peripheral vascular resistance. When peripheral vascular resistance decreases, the afterload on the heart decreases, leading to a decrease in blood pressure. Calcium antagonists as the first-line antihypertensive drugs in the five major classes of antihypertensive drugs, its antihypertensive effect is very sure, calcium antagonists have good effect in reducing either systolic or diastolic blood pressure. Therefore, if hypertensive patients take antihypertensive drugs, single drug preferred calcium antagonists or ACEI drugs, if the combination of two antihypertensive drugs, calcium antagonists in combination with ACEI drugs or ARB drugs are recommended.