The crystallinity of covellite formed by the exchange reaction of Cu²⁺ and iron-sulfide minerals in water at ambient temperature affects the recovery efficiency of Cu²⁺ and the complete degree of the exchange reaction. In this study, covellite was synthesized via direct reaction of CuCl₂ and Na₂S. The growth of covellite crystal under different conditions, including different pH values, reaction time, reaction temperatures, reactant concentrations, reactant dropping rate, and extra-added electrolyte concentrations, were discussed. The crystallinity and morphology of covellite were characterized by XRD, TEM and EDX. The average particle size of the crystal was calculated by Scherrer formula. The results showed that the lower pH values, longer reaction time, higher reaction temperature and lower reactant dropping rate had favorable effects on the growth of covellite crystals. The crystallinity of covellite increased first and then decreased with the increasing of reactant concentration, and varied with the different concentrations of extra-added ions.