Abstract: To solve the problems in the traditional cadmium extraction that the heavy consumption of raw material， high pollution for environment and low extraction rate of cadmium， a new process that extracting cadmium from copper-cadmium slag in zinc hydrometallurgy by replacement of zinc plate synergized with direct current is proposed. The experiment is conducted under different reaction conditions including current density， temperature， polar distance and pH values， the changes of the zinc， cadmium content and acidity with time are monitored and analyzed momentarily. The results showed that with the reaction carried through， the concentration of zinc ion increased， the pH values unchanged and the production sponge cadmium possessed dendrite structure by morphology analysis. This new process has a certain guiding significance to cadmium production as for reducing produ