The invention discloses a polyurethane co-mixed modified polyphenylene sulfide composite material which comprises polyphenylene sulfide, polyurethane, glass fibers, wollastonite fibers and an assistant, wherein the assistant comprises a compatilizer, an antioxidant, a coupling agent, a lubricant and carbon black. The invention further discloses a method for preparing the polyurethane co-mixed modified polyphenylene sulfide composite material. The method comprises the following steps: (1) stirring and mixing the polyphenylene sulfide, the polyurethane, the glass fibers, the wollastonite fibers, the compatilizer, the antioxidant, the coupling agent, the lubricant and the carbon black to obtain a mixed material; (2) adding the mixed material into an extruder and extruding to obtain the strip-like composite material. The polyurethane co-mixed modified polyphenylene sulfide composite material disclosed by the invention not only has the characteristics of high strength, low creep, good mobility, easiness in processing and the like, but also has the characteristics of high toughness, low density, small dielectric constant, high comparative tracking index and the like.