Aging is an irreversible life process, and the physiological functions of individuals gradually decline and degenerate with aging. As they age, the elderly experience progressive decline of cognitive functions, including memory. Memory decline in the elderly is often associated with impaired cellular physiological processes in the brain. The energy metabolism disorder exerts direct damage on the memory in the elderly, and the excessive occurrence of neuroinflammation and accumulation of abnormal metabolites seriously damage their brain microenvironment, resulting in the memory decline. From the perspectives of energy metabolism, neuroinflammation and other physiological processes related to memory, this article reviews and discusses research progress in the neurobiological basis of memory decline in the elderly in recent years.