Abstract: The moisture absorption properties of acid-leaching residue of laterite nickel and diatomite in three kinds of humidity were studied by means of desiccant method, and the moisture desorption properties of the two were compared. The particle size and pore structure of the two were analyzed and compared. The results show that the humidity controlling of acid-leaching residue lateritic nickel is better than diatomite, and its indexes such as moisture absorption, moisture absorption rate, moisture desorption and moisture desorption rate all surpass diatomite. Moreover, the specific surface area and particle size of acid-leaching residue of laterite nickel are larger than diatomite. According to the analysis of humidity controlling, acid-leaching residue of laterite nickel is suitable as an excellent humidity control material.