Cognitive dysfunction is a common adverse consequence of traumatic brain injury (TBI). After brain injury, the brain and other organs trigger a series of complex metabolic changes, including reduced glucose metabolism, enhanced lipid peroxidation, disordered neurotransmitter secretion, and imbalanced trace element synthesis. In recent years, several research and clinical studies have demonstrated that brain metabolism directly or indirectly affects cognitive dysfunction after TBI, but the mechanisms remain unclear. Drugs that improve the symptoms of cognitive dysfunction caused by TBI are under investigation and treatments that target metabolic processes are expected to improve cognitive function in the future. This review explores the impact of metabolic disorders on cognitive dysfunction after TBI and provides new strategies for the treatment of metabolic disorders. There is currently no mechanism that adequately explains cognitive impairment after traumatic brain injury (TBI).A series of metabolic disturbances, including sugars, lipids, proteins, and iron, occurs after TBI.Central metabolic disorders are the main cause of cognitive dysfunction after TBI.Metabolism-related therapies may have a bright future as a novel therapeutic strategy for cognitive impairment after TBI.