Hydrocephalus is a common medical condition characterized by abnormalities in the secretion, circulation and absorption of cerebrospinal fluid (CSF), resulting in ventricle dilatation. For the communicating hydrocephalus, without etiological treatment, its pathogenesis has been considered as a research emphasis. Many factors can damage the CSF system and trigger communicating hydrocephalus, including tumor surgery and hydrocephalus neurological diseases, such as brain trauma, infection, ICH and SAH. But according to our clinical experience, a big proportion of patients do not develop hydrocephalus. That is because the absorbing ability of CSF can compensate within a certain range. If the damage exceeds that range, hydrocephalus will occur. Once it occurs, it is not likely to be reversed, so a shunt surgery is always needed. Therefore, we believe that our orientation could transform the treatment of patient who has already showed hydrocephalus symptoms to the prevention of the occurrence in the patient with high risk of hydrocephalus. Based on the hypothesis above, we first divide the process of hydrocephalus into three stages and we believe that hydrocephalus are possible be reversed or halted in stage 1 and 2. The new concept of the pathogenesis in hydrocephalus will enrich our understanding and provide new insights to the therapeutic orientation. In conclusion, the future research direction should be the prevention of hydrocephalus, which should take a long period from the immediate occurrence of brain injury to several months or even years after the injury.