Recently, with the development of perinatal medicine in China, the establishment of neonatal intensive care unit (NICU) and the improvement of respiratory support technology, the survival rate of preterm and term neonates has been significantly improved. However, the brain development of preterm neonates is incomplete compared with that of full-term neonates. Therefore, during the extrauterine cultivation of preterm neonates, clinical intervention should be carried out according to their brain development to achieve the same development status as that of full-term neonates. There are many clinical inspection methods to monitor the brain development of preterm neonates, such as EEG, functional near-infrared spectroscopy imaging, etc. However, these technologies cannot assess the brain development of premature infants systematically and completely. Because of the existence of neurovascular coupling, brain function and cerebral blood flow are closely related, so the detection of cerebral blood flow can reflect brain development and brain function. Ultrafast ultrasound power Doppler imaging technology is an emerging, real-time, high-resolution microvascular imaging technology. In this study, we first used ultrafast ultrasound power Doppler imaging technology to image the cerebral blood flow of preterm neonates at different gestational ages to evaluate the development of cerebral blood flow of preterm and term neonates and provide guidance for the clinical intervention of preterm neonates.