The invention relates to a preparing method of antioxidant silvering copper powder. Sodium hypophosphite is adopted to serve as a reducing agent, deionized water is adopted to serve as a solvent, sodium hypophosphite reduction liquid is prepared, copper powder is adopted to serve as a base material to be added into the reduction liquid, PVP is added, ammonium hydroxide is added to adjust the pH value, and the pH value is stabilized to 11; silver nitrate serves as a silver source, the deionized water serve as a solvent to prepare oxidation liquid, an EDTA-2Na complexing agent is added, stability of plating liquid is improved, and the problem that in the silvering process, silver ions are released too fast is obviously solved; solutions are mixed, meanwhile, magnetic stirring is carried out, the adding temperature is kept to range from 30 DEG C to 80 DEG C, reaction is carried out for 20 min, centrifuging is carried out, and one-time-silvering copper powder is obtained; the one-time-silvering copper powder serves as the base material, the above steps are repeated twice, and third-time-silvering copper powder is obtained. High-temperature oxidation resistance of silver plated copper powder prepared through the method is excellent, and the method is suitable for replacing conductive phase silver powder of electronic paste.