Traumatic brain injury is one of the leading causes of death and disability worldwide. Patients with moderate to severe traumatic brain injury often experience significant cognitive impairments， including multidimensional deficits in attention， memory， executive function， and information processing speed， which severely impact their quality of life and ability to reintegrate into society. Due to the complexity of its pathogenesis and the high heterogeneity of its clinical manifestations， there is currently no unified diagnostic and treatment protocol supported by high-level evidence. This paper reviews and summarizes the neural mechanisms， assessment methods， comprehensive intervention strategies， and individualized management of cognitive impairment after moderate to severe traumatic brain injury. The aim is to establish a clinical framework of "mechanism identification， precise assessment， stratified intervention and long-term management"， providing reference for optimizing patients' cognitive rehabilitation and improving long-term prognosis.