Abstract: Disclosed are a nano silver paste and a preparation method thereof. The nano silver paste of the present application includes nano silver powder, micron-tin based solder particles, a reducing agent, a dispersing agent, and a diluent. The nano silver paste of the present application is obtained by uniformly mixing the nano silver powder, the micron-tin based solder particles, the reducing agent, the dispersing agent, and the diluent. According to the nano silver paste of the present application, the problems of nano silver paste in the prior art of low stacking density during non-pressure sintering, high porosity, severe volume contraction, susceptibility to cracking, and low interface soldering rate are solved, thereby improving the mechanical properties and reliability of sintering positions.