This work investigates the function of additives in the electrolytic preparation of copper powder under various conditions: without additive, with traditional additive, or with polyvinylpyrrolidine (PVP) and sodium polyoxyethylene alkylphenol sulfonate (APES) additives. The influences of the additive on the composition and particle size distribution of copper powder as well as on the current efficiency are also studied. The results show that the particle size distribution of copper powder cannot be reduced without additive or with traditional additive, but the mixture of PVP and APES is an ideal additive because it can make the copper powder particle size distribution reach the level of practical demand and widen the particle size distribution range.