The invention relates to the technical field of medicine, and relates specifically to a standard extract for the drug efficacy of leaves and twigs of nakedflower beautyberry and a preparation method thereof. The total content of cinnamylic acid and flavonoids is 92%-98%, wherein a percentage content ratio of the cinnamylic acid to flavonoids is (70+/-5%):(30+/-10%), and an amount ratio of the cinnamylic acid to flavonoids is (25-35):(8-16). The preparation steps of the standard extract for the drug efficacy of leaves and twigs of nakedflower beautyberry are as follows: reflux extraction with ethanol solution, purification with styrene nonpolar adsorption resin, extraction with ethyl acetate, separation by prepared HPLC, and vacuum drying. The present invention solves the problem of poor quality stability and consistency of a preparation of leaves and twigs of nakedflower beautyberry. The prepared standard extract for the drug efficacy of leaves and twigs of nakedflower beautyberry notonly has high total content of cinnamylic acid and flavonoids, but also has stable percentage content ratio and amount ratio of the cinnamylic acid and flavonoids. The standard extract for the drug efficacy of leaves and twigs of nakedflower beautyberry also has significant antibacterial, anti-inflammatory and hemostatic effects.