The invention relates to the field of pharmacy, and discloses a preparation method of polymeric nanoparticles based on double-layer synergistic controlled-release medicine delivery. The preparation method comprises the following steps: firstly, embedding a hydrophilic anticancer medicine doxorubicin hydrochloride into an oil phase system of poly(N, N-dimethylaminoethyl) methacrylate, then loading the outer surface of the oil phase of the poly(N, N-dimethylaminoethyl) methacrylate with an anticancer medicine nitrosourea chloride, and finally embedding the system into the aqueous phase of poly (N-isopropylacrylamide), and volatilizing an organic solvent to obtain the polymeric nanoparticles based on the double-layer synergistic controlled-release medicine delivery. The polymeric nanoparticles prepared by the preparation method are expected to achieve the controlled release of a double-layer anticancer medicine in the later stage and are used for treating cancer cells; meanwhile, by the preparation method, a significant effect on the cells is avoided in the later experimental process, the scientificity of an experimental result is not affected, and experimental operation process is simple, non-toxic, harmless and environment-friendly.