The invention discloses a utilization method for surplus steam in a polycrystalline silicon production process. The utilization method is characterized by comprising the following step: supplying thesurplus steam generated in the production process to a refrigerating system and a washing machine water tank and heating the surplus steam, wherein the refrigerating system is used for refrigerating water in the steam and the washing machine water tank is used for heating the washing machine water tank by utilizing the heat in the steam. By adopting the utilization method for the surplus steam inthe polycrystalline silicon production process, provided by the invention, graded comprehensive utilization of the steam is realized and the heat and the water in the steam are effectively utilized into other production equipment, so that energy sources are saved and the production cost is reduced.