Based on the KF–AlF₃–Al₂O₃ system melts are perspective media for the electrolytic production of aluminum in energy-efficient new-generation electrolyzers. In the present paper the dissolution process of Al₂O₃ in KF–AlF₃ melt with cryolite ratio [KF]/[AlF₃] = 1.5 mol/mol at the temperature of 785°С was studied using cyclic voltammetry and carbothermic recovery of melt samples on the LECO analyzer. For the measurements the construction of the electrochemical cell including glassy-carbon working electrode, gaseous CO/CO₂ reference electrode and graphite counter electrode was used. During the measurements the peak value of the current response on voltammograms was established depending on the potential sweep rate, the time of dissolution of alumina sample and the content of alumina in the melt. It is shown that the current peak value depends linearly on the content of Al₂O₃ in the studied melt, while the dissolution rate of the alumina was from от 2.4 · 10^–3 до 5.45 · 10^–5 mol/s depending on its concentration in the melt. Based on the analysis of the obtained results, the principal possibility of operational non-destructive control of the alumina (Al₂O₃) content during the electrolysis of the KF–AlF₃–Al₂O₃-based melts system, including the fixing of the current peak value on the voltage and determining the current (in real time regime) content of alumina in the melt from the empirical dependence is shown.