The invention belongs to the technical field of metallurgical purification, in particular to a method for enhancing purifying polysilicon through enhanced alloying segregation. The method comprises the following steps of firstly pre-washing industrial silicon and primary aluminum, and fully melting the primary aluminum under the protection of argon, and then adding the industrial silicon to the molten aluminum liquid, heating the mixture to 1100-1200 DEG C, and performing alloying melting; after the mixture is fully molten, adding metal or metal oxide, preserving the temperature and then slowly cooling the mixture, separating boride and primary silicon in sequence, and depositing the boride and primary silicon at the bottom of a crucible; dumping and storing the aluminum-silicon melt at the upper part of the crucible, and finally performing inorganic acid treatment on the primary silicon, removing residual metal and boride, and performing drying treatment on the treated primary silicon to obtain the polysilicon with low boron content. According to the method provided by the invention, on the basis of purification of Si-Al alloy, trace metals such as Fe, Ti, TiO2 or metal oxides are added, the purpose of removing boron impurities in the silicon can be realized, so that the boron content can meet the requirement of the solar grade silicon; the practicability is strong, the industrial production period is short, the energy is saved, the consumption is reduced, the environment is protected, the technology is stable and the production efficiency is high.