The invention discloses a method for preparing nano-scale silver powder and comprises the steps of reduction reaction, solid-liquid separation and washing and drying. In the reduction reaction, aqueous solution with the silver-bearing concentration being 30-200g/L is dropwise added into the reducing solution, or aqueous solution of reducing agent is dropwise added into silver oxide suspending liquid with the silver-bearing concentration being 30-200g/L, the reaction temperature is controlled at 20-60 DEG C, and synchronously pH regulating agent is added, the pH value of the reaction solution is controlled at 10-14, then the reaction solution is stirred to obtain the silver suspending liquid. The method process is simple and easy to carry out, the obtained nano silver powder has high purity, good dispersivity, small particle diameter, higher specific surface and tap density and high drying temperature range of the powder, the self-sintering or agglomeration of the powder can be effectively controlled, and the powder can be easily dispersed in an organic carrier.