The invention relates to a method for extracting DNA from weeping forsythia leaves, which effectively overcomes the shortcoming that weeping forsythia DNA contains proteins and has stripe dispersion of which A260/280 is equal to 1.38 and solves the problem of removing impurities such as phenols and tannin from the weeping forsythia leaves. The method comprises the following steps of: adding liquid nitrogen into a mortar to quickly grinding the weeping forsythia leaves into powder, transferring the powder into a centrifugal tube, adding extraction buffer solution into the centrifuge tube, uniformly mixing, performing ice bath, centrifuging the materials, discarding supernate, adding 2XCTAB and beta-mercaptoethanol into the obtained product, uniformly mixing, performing water bath, centrifuging the mixed materials, filling the supernate into the centrifugal tube, adding mixed solution of chloroform and isoamyl alcohol into the centrifugal tube, lightly turning the centrifugal tube up and down, uniformly mixing, centrifuging the mixture, and repeating the operation till no white precipitates appear on the supernate level; filling the supernate into the centrifugal tube, adding isopropyl alcohol into the centrifugal tube, and standing for one night; centrifuging the mixed solution, collecting precipitates, bleaching the precipitates with alcohol, reversely positioning the centrifugal tube on a piece of absorbent paper, and drying in air to obtain an air-dried product; and dissolving the air-dried product by buffer solution, adding RNase into the buffer solution, uniformly mixing and performing warm bath to obtain the DNA of the weeping forsythia leaves. The method is used for high-efficiency and high-quality DNA extraction from the weeping forsythia leaves.