Some patients may develop hydrocephalus after traumatic brain injury and require further surgical treatment, then hydrocephalus after traumatic brain injury occurs due to some of the following factors: 1, blood accumulation in the subarachnoid space, accumulation of blood fibrosis, arachnoid granules in the sagittal sinus, affecting the absorption of cerebrospinal fluid, resulting in the formation of traffic hydrocephalus; in the skull base, adhesions block the circulatory pathway of cerebrospinal fluid, resulting in obstructive hydrocephalus; 2, blood clots block the midbrain conduit or the exit of the four ventricles, causing obstructive hydrocephalus; 3, sometimes trauma causes occlusion of large venous sinuses, which obstructs venous return and leads to impaired absorption of cerebrospinal fluid, causing hydrocephalus; 4, brain contusion injury after the formation of cerebral softening foci, resulting in brain atrophy and passive enlargement of the ventricles, forming hydrocephalus.