Objective: Correlation of serum 25-hydroxyvitamin D level with senile hypertension and its stroke. Methods: Two hundred hypertensive patients admitted to the hospital from February 2022 to December 2023 were classified as study subjects. They were divided into grade 2 hypertension group and grade 3 hypertension group, and 100 healthy medical checkups admitted during the same period were analyzed as study subjects. Results: Comparison of diagnostic results between grade 2 hypertension and grade 2 hypertensive stroke patients, there was a difference in 25(OH)D, (P < 0.05). Comparison of test results between grade 3 hypertension and grade 3 hypertensive stroke patients, there was a difference in age, BMI, 25(OH)D, GLU, LDL-C, (P < 0.05). Serum 25-hydroxyvitamin D level is a high-risk factor for the occurrence of stroke in elderly hypertensive patients, so the probability of risk is higher, where 25(OH)D (ng/mL), GLU (mmol/L), there is a difference, (P < 0.05). Conclusion: There is a greater relationship between the occurrence of stroke and serum 25-hydroxyvitamin D level in elderly hypertensive patients. The occurrence of the disease has a greater relationship with this indicator in patients and is also a high-risk factor that affects the patients’ morbidity, so it is necessary to pay attention to the monitoring of this indicator after the onset of the disease in patients.