We report a highly sensitive electrolytic copper (Cu) detection method using nanoparticle enhanced laser-induced breakdown spectroscopy (NELIBS) for metal smelting processes. The sulfate solution Cu with content ranging from 10 to 50 g/L was prepared and measured on the nanoparticle chip. The experimental results showed that the Cu spectral line intensity of NELIBS increased 5.5 to 9.4 times compared with typical LIBS without nanoparticles. The calibration curve was established based on the spectral line intensity at Cu I 327.40 nm according to the different Cu content in the solution. The determination coefficient R² of the calibration curve was 0.99. The method of laser-induced breakdown spectroscopy based on drying liquid droplets on the nanoparticle chip can be applied to the rapid determination of Cu content in the copper electrolyte.