To reduce the amount of zinc leaching residue and improve the metal recycling rate in the traditional zinc smelting process, a Cu-assisted reductive leaching process of zinc leaching residue and zinc calcine was proposed in this study. In the presence of sufficient copper powder, effect of factors including sulfuric acid concentration, liquid-solid ratio, leaching temperature, and the amount of H2SO4 on the zinc leaching efficiency, the residual rate of the solid, and the residual amount of H2SO4 for zinc leaching residue and zinc calcine was investigated. The results of leaching experiment showed that for zinc leaching residue, the zinc leaching efficiency was enhanced from 32.82% to 92.82% assisted by copper, compared to the pure acid leaching process (100 g/L H2SO4, 20 mL/g, 60℃). The residual rate of the solid was decreased from 62.34wt% to 25.20wt%. Values of pH of the leaching solution were increased from 0.12 to 0.36. For zinc calcine, the zinc leaching efficiency was enhanced from 86.52% to 98.82% assisted by copper, compared to the pure acid leaching process (200 g/L H2SO4, 10 mL/g, 60℃). The residual rate of the solid was decreased from 26.56wt% to 6.28wt%. Values of pH of the leaching solution were increased from 0 to 0.19. The least concentration of the residual H2SO4 was 25~26 g/L for sufficient extraction of zinc. The Cu-assisted leaching process has advantages in metal recycling, residue reduction, and low concentration of the residual H2SO4. It supplies a new idea about in situ treatment of zinc leaching residue in zinc smelters.