Alzheimer’s disease (AD) is a degenerative disorder of the central nervous system in the elderly and the pre-aging period, whose main clinical manifestation is progressive cognitive impairment. Till now, no treatment for AD has been found effective and the drugs can only delay the progression of the disease with limited efficacy, and often accompanied by side effects. In recent years, neuromodulation, as a method of targeting stimulation to regulate the activity of target brain regions, has gained much attention. It has been widely used in the treatment and research of AD. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) modulate cortical neuronal activity and excitability by changing neuronal membrane potential. Clinical studies have shown that these two non-invasive methods can improve cognitive impairment in AD patients to a certain extent. However, due to the low spatial accuracy and various effect sizes, the optimal stimulation target area, parameters and modes of these two methods have not been unified yet. Deep brain stimulation (DBS) can improve cognitive function in AD patients by regulating cognition-related neural circuits and optogenetics stimulation precisely regulates the activity of specific neurons and neural circuits through genetic and optical means. The research results of cognitive function related circuits and specific neurons by the two innovative methods provide a theoretical basis for identifying the injury mechanism of AD cognitive impairment and the therapeutic targets at the level of brain functional network. This paper reviews the application and research status of the above mentioned four typical neuromodulation methods from the aspects of effect, mechanism, stimulation of brain area and stimulation parameters, so as to provide new ideas for the application of neuromodulation in clinical treatment of AD in the future.