_{:The effect of temperature, the distance of electrodes, conductive salt concentration, pH values and kinds of additives on the purity and size of indium powder by electrolysis process was studied. The results show that：The optimum process parameters for electrolysis are obtained. (The optimum process parameters for electrolysis as follows: The concentration of In3+ is 30g/L, the current density is 130 A/cm2, continuous electrolysis time is 1 hour, the concentration of NaCl is 80g/L, the distance of electrodes is 5cm, thiourea concentration is 0.3g/L, gelatin concentration is 0.5g/L, pH=2.5 and polyvinylpyrrolidone is 0.2g/L). Under these conditions, the distance of electrodees does not affect the purity of the powder, but affect theparticle size of the powder. The concentration of NaCl has the greatest influence on the purity of the powder.The higher temperature of the electrolyte, the particle size becomes larger and the purity of the powder decreases. The additive of thiourea restraining dendrite growth of the powder. Electrolysis 1 hour under the optimum process parameters, indium powder with a grain size of less than 100μm is obtained. The particle size less than 30μm accounted for 75%, the purity of the powder is 99.98%, and the average current efficiency is 70.10%.}