The invention belongs to the technical field of power system operation and control, and especially relates to a high-permeability wind power isolation grid frequency control method based on a polycrystalline silicon load. The method comprises the steps: carrying out the analysis of the growing process of polycrystalline silicon, building an electrical model of the polycrystalline silicon load, carrying out the fitting of voltage and current and the radius of a polycrystalline silicon rod through combining with the industrial data, and building a polycrystalline silicon load power characteristic model; obtaining a polycrystalline silicon load power control mathematic model according to the polycrystalline silicon load power characteristic model. The method can achieve the quick changing of the consumption power of the polycrystalline silicon load through changing a wave splicing voltage and wave splicing time under the condition of giving consideration to two limiting factors: incoming rate of cooling water and the temperature of the silicon rod. The method proposes a control strategy for the response of the polycrystalline silicon load to the fluctuation of the isolated grid power under the condition of giving consideration to the diversity of the polycrystalline silicon loads. The method takes a Chifeng isolated grid as the background, enables the isolated grid to maintain stable through load response power under the condition of extreme wind power fluctuation, and verifies the correctness of the proposed control strategy.