The invention provides a demulsifier composition and a lubricating oil composition containing the demulsifier composition. The demulsifier composition provided by the invention comprises: 1) a copolymer of alkyl acrylate and alpha-olefin sulfonate; 2) a copolymer of alkylphenol sulfide, propylene oxide and ethylene oxide, wherein the mass ratio of the two copolymers is (1-10):(10-1). The demulsifier composition of the invention has a high stability in lubricating oils, has an excellent oil-water separation effect and demulsifyingeffect, is especially suitable for separating trace water from the lubricating oils, and can be used for industrial gear oil, turbine oil and marine crankcase oil.