Abstract: The wastewater in iron pyrite exploitation contains lots of iron (with low acidity) and has a potential harm to environment. The treatment and utilization of iron pyrite wastewater is meaningful for environment protection. Thus，the preparation of black iron pigment from iron pyrite wastewater were explored with a wet oxidation precipitation method through regulating the pH of the original reaction solution (7—12)，reaction temperature (70—95℃)，reaction time (1—4.5h) and the stirring rate (50—250 r/min). Black iron pigment with high quality was obtained at the conditions of pH 9.5，temperature 85℃，reaction time 2.5h and stirring rate 150 r/min. XRD and SEM analysis showed that the particle size of the prepared black iron pigment is about 60nm，and Fe3O4 content is higher than 95%. The product can reach the requirements for the first-grade standard in black iron pigment industry.