An antimony diaphragm electrorefining technology suitable for tartrate system was developed using refined antimony as raw material. The effects of different diaphragm types and electrolysis process parameters including current density, electrolysis temperature, electrolyte circulation speed and electrode spacing on cathode current efficiency, cell voltage, direct current consumption, cathode antimony purity and typical impurity removal rate are systematically investigated. The optimum process conditions are determined as follows:tartrate ion mass concentration is 250 g/L, antimony ion mass concentration is 45 g/L, current density is 150 A/m², electrolysis temperature is 35 ℃, electrolyte circulation speed is 300 mL/min, electrode spacing is 70 mm. The research results show that according to the single point impurity content requirements of 5N grade high purity antimony in the national standard' high purity antimony' (GB/T 10117—2021), the impurities that are easy to exceed the standard in the antimony tartrate electrolysis system are mainly arsenic, bismuth, lead and copper. Only regulating the electrolysis process conditions can not achieve the deep removal of the above impurities. Further electrolyte purification measures are needed to ensure the batch stability of high purity antimony products, while the remaining 16 main control impurities can meet the requirements of the national standard Sb-05 by electrolytic refining. Under the optimal electrolysis conditions, the electrolyte is deeply purified with antimony-based adsorbent (polyhydroxyantimonic acid with the main phase of H₁₄Sb₁₄O₂₁(OH)₄₂) to obtain cathode antimony with a purity of 99.995% and a dense and bright surface. The average cell voltage is 0.808 V, the current efficiency is 96.27%, and the direct current consumption is 485.85 kWh/t.