Abstract: Objective To analyze the effects of Candesartan or Benazepril combined with Hydrochlorothiazide in the treatment of moderate to severe hypertension. Methods Eighty-six patients with moderate to hypertension who were treated in the Second Affiliated Hospital of Bengbu Medical College between June 2016 and July 2018 were enrolled in the study, and were randomly divided into a study group (n=43) and a control group (n=43) according to the random number table. The control group was treated with Benazepril (Specification: 10 mg*10 s, starting dose of 5mg each time, once a day) combined with Hydrochlorothiazide (Specification: 25 mg*100 s, once a day, 25 mg each time). The study group was given Dexartan (Specification: 4 mg*14 tablets, once a day, 8 mg each time) combined with Hydrochlorothiazide for treatment. The blood pressure, blood potassium and renal function, and adverse reactions were observed and compared between the two groups. Results Before treatment, there was no significant difference in blood pressure between the two groups (P>0.05). After treatment, both diastolic blood pressure and systolic blood pressure were improved in the two groups(P<0.05), with the diastolic blood pressure and systolic blood pressure in the study group, which were(77.42±8.53) mm Hg and (121.31±15.84) mm Hg, significantly better than the control group (P<0.05). The level of uric acid in the study group was (368.46±98.79) μmol/L, lower than that in the control group, which was (412.36±102.14) μmol/L, and the difference was statistically significant (P<0.05). The incidence of adverse reactions such as hypokalemia and headache in the study group was 6.98%, significantly lower than that in the control group, which was 23.26%, and the difference was statistically significant (P<0.05). Conclusion Compared with Benazepril combined with Hydrochlorothiazide, Candesartan combined with Hydrochlorothiazide is more effective in the treatment of moderate to severe hypertension, which can significantly control the blood pressure level, protect renal function, and yet incur less adverse reactions.