The aging failure mechanism of isotropic conductive adhesive under high temperature and humidity was studied. The microstructure of the material before and after aging was characterized by scanning electron microscope （SEM）， electrochemical impedance spectroscopy（EIS） and X-ray photoelectron spectroscopy（XPS）. The results show that under high temperature and high humidity， due to the post-curing shrinkage of the adhesive， the decrease in the bonding interface strength， and the difference in the thermal expansion coefficient with the bonded material， microcracks are generated at the bonding interface and expand with time. Under the same aging temperature and aging time， the presence of humidity promotes the formation and expansion of microcracks at the bonding interface. XPS results show that after aging under high temperature and high humidity， the proportion of "inorganic silicon" on the surface of the sample significantly increases.