The invention provides a preparation method of high-purity antimony. The method comprises a primary arsenic removing step, a secondary arsenic removing step, and a lead removing step. In the primary arsenic removing step, an arsenic-removing agent is one selected from sodium carbonate, potassium carbonate, sodium oxide, and potassium oxide. In the secondary arsenic removing step, an arsenic-removing agent is one selected from sodium carbonate, potassium carbonate, sodium oxide, and potassium oxide. In the lead removing step, a lead-removing agent is a mixture of one selected from diphosphorus oxide, boric acid, boron oxide, and sodium borate and one selected from sodium carbonate, potassium carbonate, sodium oxide, and potassium oxide. The high-purity antimony preparation method provided by the invention can also comprise a distillation step. The distillation step comprises the processes that: antimony obtained after the lead removing step is crushed and placed in a vacuum distillation furnace for distillation treatment. With the high-purity antimony preparation method provided by the invention, impurities arsenic and lead in raw material antimony can be effectively removed, and high-purity 5N antimony can be prepared. The method is safe and reliable, and has the advantages of simple process, easy operation, no pollution to the environment, and low production cost.