Objective. To evaluate the efficacy of calcium carbonate-vitamin D3 in pregnant women for the prevention of hypertensive disorders in pregnancy. Methods. Between April 2020 and June 2021, 60 pregnant women undergoing prenatal examinations in our hospital were recruited and assigned via the random number table method at a ratio of 1 : 1 to receive conventional pregnancy care (observation group) or conventional pregnancy care plus calcium carbonate-vitamin D3 administration (experimental group). Outcome measures included blood pressure, blood calcium, the occurrence of hypertensive disorders, and adverse events. Results. The diastolic blood pressure (DBP) and systolic blood pressure (SBP) levels at delivery in the experimental group were significantly lower than those in the observation group ( P < 0.05 ). Pregnant women in the experimental group had significantly higher blood calcium levels at labor than those in the observation group ( P < 0.05 ). The administration of calcium carbonate-vitamin D3 resulted in a significantly lower incidence of hypertensive disorders and adverse events versus conventional pregnancy care ( P < 0.05 ). Conclusion. The effect of calcium carbonate-vitamin D3 administration during pregnancy for the prevention of hypertensive disorders is significant, which effectively improves the blood calcium level of pregnant women and reduces the occurrence of adverse events, so it is worthy of clinical promotion and application.