Method for preparing magnesium hydroxide by dry method

The invention discloses a method for preparing magnesium hydroxide by a dry method, which comprises the following steps of: putting magnesium oxide into a hydrater, adding a catalyst and water, releasing a large amount of heat through catalysis in the hydration process of magnesium oxide, heating to 98-110 DEG C, carrying out intense reaction for 3-5 minutes, slowly reducing the temperature afterintense reaction, keeping the temperature at 96-98 DEG C for 30 minutes, then conveying the formed magnesium hydroxide dry powder to a curing bin, continuing to cure the material, and generating the magnesium hydroxide dry powder through airflow conveying, cooling and packaging. According to the method for preparing magnesium hydroxide by the dry method, the hydration rate is as high as 98%, no external energy is needed, and the effects of energy conservation, environmental protection, no waste water, no waste residue or no waste gas, simple process, simple equipment and cost saving are achieved; and the whole process