The invention discloses a hydrophilic modification method of a PVDF multihole film, relates to a film modification method, belongs to the field of multihole film modifying, and aims at solving the technical problems that the PVDF multihole film is high in hydrophobicity, the driving force needed in the separating process is large, the water flux is low, and the PVDF multihole film is contaminated easily in the using process. The hydrophilic modification method comprises the following steps that a solution with the mass concentration of 2-acrylamide-2-methyl propanesulfonic acid ranging from 20 percent to 40 percent is prepared, methyl methacrylate and azodiisobutyronitrile are added to the solution, and a reaction system is obtained; the reaction system is heated, reduced pressure distillation is carried out, the reaction system is poured into precipitator, precipitate is obtained and dried, and copolymer is obtained; the copolymer, polyvinylidene fluoride and polyvinylpyrrolidone are added to dimethylformamide to be stirred and cooled to the indoor temperature, the mixture is subjected to standing, and casting film liquid is obtained; the casting film liquid is poured to a glass plate on a film laying machine for film laying, the casting film liquid is dried, and then the PVDF multihole film is obtained. The modified PVDF multihole film is high in hydrophilia.