Alzheimer's disease (AD) is the most common cause of dementia, and its morbidity increases rapidly, bringing a heavy burden to society. At present, drug therapy is the main treatment but unfortunately, with limited effect. According to the current AD research, amyloid deposition, pathologic tau, and neurodegeneration are most often studied for the diagnosis and treatment of AD, however, they have the disadvantages of high cost and invasion. Therefore, there is a urgent demand for novel and valid techniques for the diagnosis and treatment of AD. Transcranial magnetic stimulation (TMS) can reveal the excitability of the motor cortex, reflect the alternative pathophysiology of diseases, and is being increasingly applied for AD diagnosis and treatment. Previous studies have shown that TMS can detect the neurophysiological changes in the cortex of AD patients at the prodromal stage of the disease, and compared to the well-established biomarkers, TMS has the value of diagnosis and differential diagnosis. Because of it is non-invasive, convenient, and inexpensive, TMS has the potential to become a biomarker of AD and other degenerative disease. In addition, TMS has been used in the treatment for AD and achieved promising clinical effects. This review focus on the advances in the studies of TMS, to analyze the application of TMS in the study and treatment of AD.