The invention relates to a method for preparing antioxidant soldering powder, comprising the following steps: adding soldering powder to solution containing 5-25 percent by weight of active agent and 2-20 percent by weight of coating agent; stirring the active agent, the coating agent and the soldering powder at the temperature of 30-80 DEG lower than the soldering powder melting point so that the soldering powder suspending in the solution for 10-90 min; and filtering the solution, eluting the solution with solvent and drying the solution in vacuum to obtain the antioxidant soldering powder. The invention is suitable for coating the alloy soldering powder such as SnPb soldering powder, SnPbAg soldering powder, SnPbBi soldering powder, SnBi soldering powder, SnCu soldering powder, SnBiCu soldering powder, SnAg soldering powder, SnAgCu soldering powder and SnZn soldering powder of any particle size and is particularly suitable for coating the alloy soldering power of small particle size or the alloy soldering power which is easily oxidized. The soldering powder is coated by removing an oxidation layer on the surface of the soldering powder, thus the effect of coating the soldering power with the coating agent is improved, the shelf life of the soldering powder is prolonged, the requirements for the package, the storage and the transportation of the soldering powder are lowered, the cost is saved and the waste of the resources is reduced.