Alzheimer's disease （AD） is the most common chronic neurodegenerative disease in the elderly aged ≥65 years， and its incidence rate increases with age. The main manifestations of the patients with AD included cognitive impairment such as aphasia and agnosia and mental symptoms such as behavioral abnormalities. AD often involves multiple systems and has complex etiologies and unclear pathological mechanisms， and at present， there are still no specific drugs for the treatment of AD， which can only delay the progression of the disease. An analysis of related articles shows that the physiological and pathological bases of AD include various factors such as abnormal deposition of β-amyloid （Aβ）， abnormal phosphorylation of tau protein， decreased content and activity of acetylcholine， glutamate toxicity， autophagy， inflammatory response， and some vascular diseases. Up to now， five drugs have been approved by the US Food and Drug Administration for clinical application， among which tacrine， donepezil， rivastigmine， and galantamine are acetylcholinesterase inhibitors and memantine is an N-methyl-D-aspartate receptor antagonist， and this article briefly describes these five drugs in terms of mechanism of action， indication， method of administration， and adverse reactions. Moreover， this article focuses on some new drugs under clinical trials which target the pathological changes of excessive deposition of Aβ and abnormal phosphorylation of tau protein， and the main mechanism of such drugs is to reduce the production of Aβ， prevent the deposition of Aβ， accelerate the clearance of Aβ， stabilize microtubules， prevent tau aggregation， and accelerate the clearance of tau protein. However， most therapeutic drugs have failed to achieve a satisfactory effect in clinic trials， and clinical trials are terminated due to excessive adverse effects or poor efficacy， such as LY2811376 and verubecestat； some drugs are still being evaluated in phase II or III trials， such as azeliragon and gosuranemab. Through this literature review， this article aims to identify the possible pathophysiological mechanisms in the development and progression of AD， summarize currently available therapeutic drugs， describe the bottlenecks encountered in the development of drugs， and propose possible action targets and therapeutic strategies for drug research and development in the future， in order to provide new ideas and new methods for future pharmacotherapy for AD.