The invention discloses butadiene-styrene latex and a preparation method thereof. The butadiene-styrene latex is prepared from water phase materials (a first solvent, divinylbenzene, an anionic emulsifier, a first emulsifier, hydroxyl ethyl cellulose, polysorbate-80, acrylic acid, N-methylol acrylamide, acrylic amide, and a pH regulator), oil phase materials (styrene, butadiene, an organic solvent, and 3-mercaptobutyrate), base materials (mbs seed latex, sodium dodecylbenzenesulfonate and a second solvent), and other materials (a third solvent, EDTA, initiator mixture, a water-based foam suppressor, liquid base, and a second emulsifier), wherein both the first emulsifier and the second emulsifier are non-ionic emulsifiers, the first solvent, the second solvent and the third solvent are allsoft water, and the organic solvent comprises one of butyl acetate, butyl acetate, and butyl acrylate. The butadiene-styrene latex has advantages of good water resistance, aggregate stability, mechanical stability, and chemical stability.