Traumatic brain injury (TBI) can lead to a breakdown of the blood-brain barrier (BBB), which can exacerbate brain damage. Basic fibroblast growth factor (bFGF) has a neuroprotective effect, but its effect on BBB integrity after TBI and its underlying mechanism remain unclear. To investigate the changes of BBB-related protein expression in TBI model rat astrocytes under bFGF intervention, and the regulatory role of PI3K/mTOR signaling pathway in this process. The study used animal models to simulate TBI and administered different doses of bFGF intervention. The integrity of BBB was assessed by measuring cerebral water content (BWC) and histological observation. Western blot results showed that bFGF treatment up-regulated BBB-related protein expression in astrocytes and activated PI3K/mTOR signaling pathway. bFGF promotes the expression of BBB-related protein molecules in astrocytes after TBI by activating PI3K/mTOR signaling pathway, thereby improving the integrity of BBB and playing a neuroprotective role.