Abstract: Due to the large stock, low whiteness and high heavy metal content, the recovery of acid leaching residue of laterite nickel in related fields is severely restricted. Therefore, purification and whitening has become an urgent technical problem to be solved for the efficient comprehensively utilizing of this solid waste resources. In this paper, the two-stage roasting process, that is, a process of directly calcining and ammonium sulfate calcining, was adopted to increase the whiteness. Then the process of ultrasonic dispersion leaching and centrifugal purification were used to remove the impurities affecting the whiteness of the acid leaching residue. The whiteness, the chemical composition, the mineral composition, the particle morphology and the pore structure of the samples were characterized. The results showed that the optimum whitening process was pre-calcined at 500℃ for 1 h, calcined with ammonium sulfate of 200% nickel slag quality for 2 h, ultrasonically dispersed for 8 min, and centrifuged for 1 min under a centrifugal separation factor of 4. Finally, the whiteness of acid leaching residue of laterite nickel increased from 56% to 84%. The iron content decreased from 0.92% to 0.2%. The specific surface area increased from 84 m²/g to 96 m²/g, and the recovery reached 47%. The purity and whiteness of the obtained acid leaching residue of laterite nickel were significantly improved, meanwhile the particle size was reduced and the pore structure characteristics were optimized. Therefore, its high-value development has broad application prospects.