The invention discloses a method for preparing nano electronic paste. The method comprises the following steps: preparing a low-viscosity organic phase, namely stirring for mixing aids, solvents and 10-60% of measuring resins; 2, dispersing nano powder, namely adding measured nano powder and the low-viscosity organic phase into a slurry barrel, performing ultrasonic assisted stirring so as to obtain nano dispersion; and 3, performing viscosity regulation and filtration on the slurry, namely adding the residual 40-90% of resins into the nano dispersion, stirring at a low speed by using a dispersion machine until the resins are completely dissolved, performing filter pressing, thereby obtaining the nano electronic paste. The preparation method has the following advantages that 1, the low-viscosity organic phase contributes to completely stretching the resins and aids so as to form surface bonding with the nano powder, and the dispersion stability of the dispersion is improved; 2, the residual resins are added during paste viscosity regulation and are stirred at a low speed, so that the molecular structure can be well protected, and the repeatability and stability of the paste can be guaranteed; and 3, the nanometer material dispersion efficiency is high, the process is simple and controllable, and the paste fineness is less than 2mu m.