The effects of additives such as NH 2OH·H 2O, sucrose, calcium gluconate on the qualities of cuprous oxide and the action mechanism in the process of electrolysis were studied. The results suggested that NH 2OH·H 2O and sucrose can inhibit the deposition of CuO, but can not inhibit the deposition of copper in the electrolysis process. Calcium gluconate can not only effectively prevent the deposition of spongy copper powder on the cathodes, but also reduce the CuO content in the Cu 2O product. So NH 2OH·H 2O and sucrose can be used as auxiliary additives in the electrolysis process. Calcium gluconate is a kink of ideal additive in the process of electrolysis to produce cuprous oxide, and can be used as an independent additive in the electrolysis process.