To explore the correlation between cognitive dysfunction and H-type hypertension and cerebral hemodynamics in patients with cerebral small vessel disease (CSVD). Methods: Ninety-six patients with CSVD and essential hypertension were selected. The Montreal Cognitive Assessment Scale (MoCA) was used to assess cognitive function, and transcranial Doppler ultrasound (TCD) was used to examine cerebral hemodynamics. Patients were divided into the non-H-type hypertension group and H-type hypertension group according to homocysteine (Hcy) level. Patients were also divided based on cognitive function into the no cognitive impairment (NCI) group and vascular cognitive impairment no dementia (VCIND) group. Clinical data of two groups were compared. Results: Compared with the non-H-type hypertension group, the H-type hypertension group had a lower MoCA score (P<0.05) and higher middle cerebral artery pulsatility index (MCA-PI) and anterior cerebral artery pulsatility index (ACA-PI) values (P<0.05). There was no significant difference between the two groups in mean flow velocity (Vm) of the MCA and ACA (P>0.05). The Hcy level and MCA-PI and ACA-PI values of the VCIND group were higher than those of the NCI group (P<0.05); the MCA-Vm and ACA-Vm were not significantly different between the two groups (P>0.05). Multiple linear regression analysis showed that Hcy level was negatively correlated with MoCA score (P<0.05) and positively correlated with MCA-PI (P<0.05) and ACA-PI (P<0.05). MCA-PI was negatively correlated with MoCA score (P<0.05), while ACA-PI showed no correlation with MoCA score. Conclusion: In H-type hypertension, elevated plasma Hcy levels may be a key factor in promoting and aggravating cognitive impairment. The PI value may be an important parameter when evaluating deep vascular lesions and cognitive impairment.