In this paper, the formation process of magnesium hydroxide unit cells, as well as the structural characteristics and growth morphology of magnesium hydroxide, is discussed from the perspective of growth units. The growth process of the hexagonal structure of the magnesium hydroxide is as follows: the growth units are first incorporated into a larger hexagonal dimension unit on the same plane, and then the hexagonal layers connect to each other in the z-axis direction for the hexagonal magnesium hydroxide unit cell. The results of the study show that the model of anion coordination polyhedron growth units may be reasonably deduced by using the unit cell structure and growth mechanism of magnesium hydroxide. After using Raman spectroscopy of the magnesium hydroxide growth solution Raman shift, the growth units of the magnesium hydroxide are shown to be octahedral: [Mg - (OH)(6)](4-).