The influence of different content of lignin sulfonate on the vanadium battery cathode electrolyte is analyzed by the electrochemical method.AC impedance，UV-visible spectra and single battery charge/discharge experiments have verified the effect of lignin sulfonate added.The results show that the dosage is 0.1%，the charge transfer resistance decreases from 5.446 Ω·cm2 to 1.002 Ω·cm2，the double layer capacitance of 4.16 × 10-4 F·cm-2 is reduced to 1.298 × 10-4 F·cm-2.It can indicate that the different content of lignin sulfonate did not significantly affect the excitation wavelength and absorbance，but greatly improve the charge-discharge performance.The lignin sulfonate has a strong chemical and electrochemical stability help to improve the vanadium ion conduction and electrical energy storage.