Lithium battery electrolyte and lithium battery

The invention relates to lithium battery electrolyte which is prepared from lithium salt, an organic solvent and additives. The additives include the additive S accounting for 0.1-10% of the total mass of the lithium battery electrolyte, the additive S is one or more of elements in the following structural formula (shown in the description), wherein R1-R5 are independently selected from H, halogen, nitryl, amino, cyano, alkyl substituted by the halogen or not substituted by the halogen, alkoxy substituted by the halogen or not substituted by the halogen, alkenyl substituted by the halogen or not substituted by the halogen, R6 represents alkyl, the halogen substituted by the halogen is F, Cl and Br, and the substitution performed by the halogen is partial or complete. The overcharge, charge and discharge performance of a lithium battery are all improved, side reaction is reduced, expansion of the battery under high temperature is decreased, and the cycle life of the battery under normal temperature, high temperature and low temperature is prolonged.