Objective To observe the changes of craniocerebral ultrasound parameters in neonates with hypoxic-ischemic encephalopathy (HIE), and to analyze the relationship between the above changes and disease severity, prognosis. Methods A total of 75 children with HIE admitted to neonatal intensive care unit of the hospital were enrolled between February and November 2022. According to disease severity, they were divided into mild group (38 cases), moderate group (24 cases) and severe group (13 cases). A total of 75 healthy neonates during the same period were enrolled as control group. At 48h and 72h after birth, all underwent transcranial Doppler sonography (TCD). The relevant parameters of cerebral hemodynamics were collected, and their differences among all the groups were compared. HIE children were followed up for 28d, and then they were given TCD reexamination and prognosis assessment. The correlation was analyzed by Peason method. Results At 48h after birth, peak systolic velocity (Vs), end-diastolic velocity (Vd) and mean velocity (Vm) were the highest in control group, followed by mild group, moderate group and severe group (P<0.05), while resistance index (RI) was on the contrary (P<0.05). At 72h after birth, there was no significant difference in all parameters between mild group and control group (P<0.05). At 72h after birth, Vs, Vd and Vm were the highest in control group, followed by moderate group and severe group (P<0.05), while RI was on the contrary (P<0.05). At 28d after birth, score of neonatal behavioral neurological assessment (NBNA), Vs, Vd and Vm in patients with poor prognosis were all lower than those with good prognosis, while RI was higher than that with good prognosis (P<0.05). At 28d after birth, Vs, Vd and Vm were positively correlated with NBNA score (r=0.493,0.434,0.432, P<0.05), while RI was negatively correlated with it (r=-0.478, P<0.05). Conclusion With the aggravation of disease, Vs, Vd and Vm decrease, while RI increases in HIE children. The monitoring of TCD cerebral hemodynamics parameters can objectively reflect the changes of cerebral blood perfusion, and all have certain guidance significance for prognosis evaluation.