The fabrication of nano-silver joints was done using the pressureless sintering technology to suit the demand of high-power electronics. Porosity of 10.6% and shear strength of 39.6 MPa were reached under the optimized parameters of 300℃ sintering temperature and 45 min residence time. The sintered joint demonstrated good mechanical/thermal/electrical performance in reliability testing, including the temperature cycling test, second sintering test, steady-state lifetime test, and intermittent lifetime test. This study demonstrated the viability of pressureless sintering of nano-silver joints with good high-temperature reliability, which has significant application potential for aeronautical power electronics.