Abstract: Thermodynamic properties of electrolysis process were studied by cyclic voltammetry. Theresults show that the electrode reactions in the stable electrolysis region are irreversible. The diffusionvelocity of Na₂WO₄ is an important factor of restricting electrolysis rate. CuO was added into the KCl-NaCl mixed salt electrolyte and cell voltage 1 V for 2 h at the temperature of 750 ℃. Then Na₂WO₄ wasadded and cell voltage 2 V for 3 h. X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) andEDS show that tungsten-copper alloy powder can be prepared cathode and purity can achieve 98 %.