The invention discloses a method for extracting starch of the overground part of Ipomoea batatas(L.) Lam.. The method includes sampling, grinding, filtering, centrifuging, impurity removing, starch collection and other steps, and comprises the specific steps: adopting fresh leaves, petioles or stalks of Ipomoea batatas(L.) Lam., or samples of fresh Ipomoea batatas(L.) Lam. leaves, petioles or stalks which are picked and frozen for storage immediately as extraction materials, adopting a 0.1% NaOH solution as an extraction medium, performing filtration with nylon mesh fabric of 100 meshes and 200 meshes sequentially, controlling the centrifugal rotation speed at 6000 g, scraping off impurities after each centrifugation and removal of the supernatant, performing washing and drying, and collecting the starch. The method has the advantages of simple and fast operation, cost saving, high extraction efficiency and low cost, the purity of the obtained starch is high, and no damage is caused; and therefore, the method is suitable for extraction of starch from the leaves, petioles or stalks of Ipomoea batatas(L.) Lam., and is beneficial to make full use of the starch resource of the overground part of Ipomoea batatas(L.) Lam..