In order to explore the application reliability of nano-silver pastes in high-power electronic devices， it is necessary to obtain the sintering characteristics and thermo-mechanical properties of sintered nano-silver.By varying sintering temperature， sintering time， heating rate and sintering method， the mechanical strength of sintered nano-silver is investigated with systematical observations of material morphology. Furthermore， the thermal conductivity of sintered nano-silver is compared with the conventional die-attach materials in aerospace electronic products such as Au80Sn20 solder， Sn96.5Ag3.0Cu0.5 solder， and H20E adhesive. The results indicate that the shear strength up to 40 MPa can be achieved from those nano-silver samples prepared at the temperature of 200 ℃ for 90 min in air atmosphere with a controllable heating rate. It is also found that the sintered nano-silver has a similar thermal conductivity with the Au80Sn20 solder， which is significantly greater than H20E adhesive and Sn96.5Ag3.0Cu0.5 solder. After harsh thermal and mechanical experiments， the shear strength of sintered nano-silver remains stable， which confirms that nano-silver pastes with high thermal conductivities can serve as bonding materials for potential aerospace applications in the assembly of high-power devices.