This invention discloses a method for preparing high-purity copper salt from analytical grade copper salt, belonging to the field of high-purity inorganic chemical preparation and fine purification technology. The method includes the following steps: (1) preparing a high-concentration stock solution; (2) fractional dilution treatment; (3) selective adsorption treatment; (4) fractional recrystallization; and (5) washing and drying treatment. This invention prepares high-purity copper salt with a total metalimpurity content of less than 20 ppm and a purity higher than 99.99% through selective complexation-adsorption with an oxygen donor-containing adsorbent material and fractional recrystallization. This invention is applicable to the preparation of high-purity copper sulfate, copper chloride, copper nitrate, and other products.