The invention discloses electrolyte for a secondary battery. The electrolyte is prepared from the following raw materials including acid sulfate, solvents and additives, wherein the acid sulfate is prepared by mixing sodium hydrogensulfate and potassium hydrogensulfate; the solvents are one kind of materials or a composition of a plurality of kinds of materials from water, maleic acid, tetrahydrofurfuryl alcohol, a boric acid solution, porphyrin, acrylic acid, dibutyl carbonate, isoamyl acetate, povidon iodine, triethyl phosphate and water glass; the additives are prepared from the following raw materials including lithium borate oxalate, glycol sulfite, sodium chromate, carboxymethyl chitosan, sodium selenite and potassium clavulanate. The electrolyte for the secondary battery has the advantages that each performance completely conforms to the national standard; the defects of long formation time, non-thorough formation and poor uniformity in the ordinary lead acid storage battery canbe successfully overcome; the stability of the battery is greatly improved.