The invention particularly relates to high-voltage electrolyte used for a lithium oil battery. The high-voltage electrolyte is prepared from non-water organic solvent, lithium salt and additive solvent. Additives contain cyano sulfonate ester compounds. The capacity retention ratio and the capacity recovery ratio of the lithium ion battery using the high-voltage electrolyte are both kept at 90% or above. In addition, the capacity retention ratios of 300 times of circulation all reach 88% or above. In conclusion, by means of the high-voltage electrolyte, the circulation performance of the lithium ion battery under the high-voltage condition can be greatly improved, and high-voltage lithium ion batteries can be easily obtained.