Alzheimer’s disease（AD）is the most common type of neurodegenerative disorder. Mounting evidence suggest that genetic factors play crucial roles in the pathogenesis of AD. The triggering receptor expressed on myeloid cells 2（TREM2）gene is a recently identified susceptibility gene for AD. Here，our previous findings and the recent high-quality studies are comprehensively reviewed regarding the association of TREM2 variants with AD risk，the structure，ligand and downstream signaling of TREM2，the involvement of TREM2 in AD progression，and targeting TREM2 for AD treatment. This review will offer further insights into the genetic and pathogenic mechanisms of AD and provide reference for the development of novel AD therapies.