NOVELTY - A vanadyl sulfate electrolyte preparing method involves taking sodium hydroxide and vanadium extract, adding vanadyl sulfate solution, extracting P507: TBP: sulfonating kerosene in vanadyl sulfate to obtain two-phase extract. The obtained two-phase extract is separated, loaded with vanadium organic phase and washed to obtain back-extract. The obtained back extract is added with aqueous ammonia and citric acid, extracted, washed, loaded with vanadium organic phase to obtain a vanadyl sulfate electrolyte precursor followed by distilling the obtained precursor to obtain the finished product.    USE - Method for preparing vanadyl sulfate electrolyte for use in a vanadium battery.    ADVANTAGE - The method enables preparing the vanadyl sulfate electrolyte with high purity in a simple and cost-effective manner.    DETAILED DESCRIPTION - A vanadyl sulfate electrolyte preparing method involves taking sodium hydroxide and stone coal vanadium extract, adding vanadyl sulfate solution for maintaining pH to 3.0-4.0, adding 5 times of anhydrous sodium sulfite according to a divalent oxide reducing agent, taking mixed extracting agent of P507: TBP: sulfonating kerosene in vanadyl sulfate solution by using multistage counter-current extraction for 30 minutes at 0/A=4:1 to obtain two-phase extract. The obtained two-phase extract is separated, washed with deionized water, loaded with vanadium organic phase and compared with 0/A=10:1, washed using 100 g/l sulfuric acid solution for 5 minutes in multi-stage counter-current reverse extraction loaded with vanadium organic phase to obtain back-extracted liquid. The obtained back extracted liquid is added with aqueous ammonia and added with citric acid to adjust the solution potential value to 100 mV, and extracted for 20 minutes, washed with 50 g/l sulfuric acid solution loaded vanadium organic phase for 5 minutes, compared to 0/A=3:1 by using multi-stage countercurrent extraction to obtain a vanadyl sulfate electrolyte precursor followed by distilling the obtained vanadyl sulfate electrolyte precursor to the mass of 70% to obtain the finished product.