Abstract: A thermal conductivity and insulating adhesive was prepared by diamond particle,epoxy resin(E-20),methanol etherified amino resin and additives.The adhesive was cured by drying at 130℃ for 30minutes and then at 210℃ for 10minutes.The thermal conductivity coefficient when the cured adhesive shows a transition from increasing to decreasing with the increasing of the diamond particle volume content in the adhesive.Diamond particles with large size can enlarge physical contact area between diamond particles,which improve the thermal conductivity of the cured adhesive.The thermal conductivity of the cured adhesive was simulated by the commonly used empirical models.The simulation results indicated that the Maxwell equation was in accordance with the thermal conductivity coefficient when the cured adhesive with the volume ratio of the diamond particle was less than 16.6%,while Bruggeman model and Agari model were in agreement with the experimental data when the cured adhesive with the volume ratio of the diamond particle was from 16.6% to 44.7%.