The invention relates to the field to bio-pharmaceuticals, specifically to a transdermal drug delivery preparation. The 5-fluorouracil nanoparticle transdermal drug delivery electret preparation for treating hypertrophic scars based on the action of electric field in the invention comprises a backing layer, a drug-containing pressure-sensitive adhesive layer arranged at the inner side of the backing layer and an electret layer prepared from an electret material and arranged at the outer side of the backing layer, wherein the electret layer, the backing layer and the drug-containing pressure-sensitive adhesive layer form a storage type patch. According to the invention, in virtue of the electret, the preparation can store space charges and dipole charges for a long time, has good chemical stability, good anti-wet performance, high surface potential, good charge stability and strong driving force and can totally meet special requirements of transdermal absorption; moreover, since the electret is used as a physical regulation and control factor, the preparation can provide an electrostatic field and microcurrent for the skin as an ion driving source, regulates and controls the electret state and electric structure of the skin and improves transdermal absorption of an ionic drug.