Neurodegenerative diseases are a series of diseases in which central nervous system neurons undergo progressive degeneration and necrosis. They finally lead to degeneration or even loss of brain function. Perioperative cognitive disorder (PCD) is similar to neurodegenerative diseases in pathogenesis and clinical manifestations. This disease cause serious and continued damage to patients because nerve injury is not easy to recovery and repair. Thus, there is no effective treatment method for these kinds of diseases. This paper introduces the distribution of telomerase system in central nervous system, analyzes its influence on the pathological process of neurodegenerative diseases, summarizes its role in the disease and then explores its relationship with PCD, which provides a reference for subsequent research.