Abstract: The present invention discloses a selective butyrylcholinesterase inhibitor having a general formula (I) or a pharmaceutically acceptable salt thereof, a preparation method and use thereof. The treatment efficacy of Alzheimer’s disease, especially moderate to severe Alzheimer’s disease, is tested through butyrylcholinesterase inhibitory activity, selectivity screening and toxicity to nerve cells as a carrier, and it is found that it has good target activity in vitro, extremely high selectivity and drug safety, can be used as a lead substance for further development of the treatment of Alzheimer’s disease by selectively inhibiting butyrylcholinesterase.