Mechanisms such as repair of mutilated brain cells and compensatory brain cell function remodeling must be in a stable state of the brain internal environment in order to function efficiently. The integrity of the skull and the stability of the cranial contents (brain tissue, blood, and cerebrospinal fluid) are the basis for maintaining a stable internal environment for brain function. In contrast, changes in cranial bone confinement, changes in brain tissue volume, increases or decreases in blood supply, and changes in circulatory flow of cerebrospinal fluid all lead to disturbances in the intracranial environment. Among them, cranial defects, hydrocephalus, intracranial fluid, brain tissue loss and atrophy, which are common complications after brain injury, are all hindering factors affecting the recovery of brain function. The management of the above complications is the process of structural reconstruction of the cranial brain, and the process of functional reconstruction of brain cell repair can only be realized after structural reconstruction of the cranial brain. The assessment and management of these complications need to be completed prior to the implementation of rehabilitation training in order to ensure the most efficient and maximum recovery of the damaged brain function. To make an analogy, the cranial confinement is like the air conditioning system of a room, the cerebral blood flow is like the electrical circuit system of a room, and the cerebrospinal fluid circulation is like the water and sewage system of a room. Only when the above-mentioned systems are regulated in a stable working state, the room will be a room with perfect functions, and the human brain cells living in the room will have vitality.