Toughening agent for strengthening impact resistance of prepreg

The invention provides a flexibilizer as well as a preparation method and application thereof. The flexibilizer provided by the invention is prepared from an oil-phase mixture and a water-phase mixture, the mass percentage ratio of the oil-phase mixture to the water-phase mixture is (1: 0.7)-(1: 1.8); the oil phase mixture comprises thermoplastic plastic and an organic solvent; the water-phase mixture comprises polyvinyl alcohol and deionized water; the oil-phase mixture comprises the following components in percentage by mass: 5-20% of thermoplastic plastic and 80-95% of organic solvent; the water-phase mixture comprises the following components in percentage by mass: 3-18% of polyvinyl alcohol and 82-97% of deionized water; the organic solvent is a single organic solvent or a composite organic solvent, the single organic solvent comprises N-methyl-2-pyrrolidone, and the composite organic solvent comprises methanol and trichloromethane. The prepreg and the carbon fiber reinforced composite material prepared