Objective To investigate the efficacy and safety of nifedipine tablets combined with labetalol in the treatment of hypertensive diseases during pregnancy (HDCP). Methods 79 patients with HDCP admitted to our hospital from January 2023 to July 2024 were selected as the study objects. The patients were divided into control group (39 cases) and observation group (40 cases) by random number table method. The control group was treated with nifedipine tablets; Observation group was treated with labetalol on the basis of control group. Blood pressure (diastolic pressure, systolic pressure), oxidative stress index [superoxide dismutase (SOD), nitric oxide (NO), plasma endothelin-1 (ET-1)], hemorheology index (plasma viscosity, erythrocyte specific volume), occurrence of adverse reactions and adverse pregnancy outcome of the two groups were analyzed and compared. Results After 14 days of treatment, the diastolic blood pressure and systolic blood pressure in both groups were significantly lower than before treatment, and the diastolic blood pressure and systolic blood pressure in the observation group were significantly lower than those in the control group (P < 0.05). After treatment, SOD and NO in both groups were significantly higher than before treatment, and ET-1 was significantly lower than before treatment, and the changes of SOD, NO and ET-1 in observation group were significantly greater than those in control group (P < 0.05). After 14 days of treatment, the plasma viscosity and erythrocyte specific volume of both groups were significantly lower than those before treatment, and the plasma viscosity and erythrocyte specific volume of the observation group were significantly lower than those of the control group (P < 0.05). There was no significant difference in the incidence of adverse reactions between the two groups (P > 0.05). The incidence of adverse pregnancy outcome in observation group was significantly lower than that in control group (P < 0.05). Conclusion Nifedipine tablets combined with labetalol in the treatment of HDCP can reduce blood pressure, improve hemorheology, alleviate vascular endothelial injury, and reduce adverse pregnancy outcomes without increasing adverse reactions.