Objective To observe the clinical efficacy and safety of nifedipine controlled-release tablets on the antihypertensive effect of hypertensive patients under high altitude environment. Methods 42 hypertensive inpatients in the 940th hospital (altitude 1500 ) were set to the plain hypertension group, and 42 cases of hypertensive inpatients in Bayi hospital (altitude 3800 m) were set to the plateau hypertension group. Both groups of patients were given nifedipine controlled-release tablets 30 mg daily, taken orally in the morning for 6 consecutive days. Monitor blood pressure and heart rate three times a day to compare the clinical efficacy and occurrence of adverse drug reactions in the two groups. Results After treatment, the total effective rates of the high-altitude hypertension group and the plain hypertension group were 47.62% (20 cases/42 cases) and 76.19% (32 cases/42 cases) respectively with no statistical difference (P<0.05). The adverse drug reactions of the two groups of patients were tachycardia and palpitations. The incidence of total adverse drug reactions in the high-altitude hypertension group and the plain hypertension group were 14.29% and 11.90% respectively with no statistical difference (P>0.05). Conclusion The high-altitude hypoxic environment could affect the antihypertensive effect of nifedipine controlled-release tablets, which could not control the patient's blood pressure effectively in the short term.