Abstract: In recent years, the third-generation materials represented by GaN and Si C have attracted much attention in the field of power devices, so the performance of interconnection materials in high-temperature environments has higher requirements. The copper substrate and frame were assembled by sintering the nano-silver paste with high thermal conductivity, and the nano-silver sintered interconnect chip substrate sample was prepared, and then the interconnection joint with high strength was obtained; and the key properties such as electrical and thermal conductivity of this conection material were tested by a variety of equipment, and the influence of different sintering temperature, sintering time and other factors on the shear strength of the sintered silver joint was studied. The results show that the optimal sintering temperature is determined to be between 250-300 ℃; the material can meet the needs of high-power electronic devices for high-temperature service.