The invention discloses a method using co-precipitation to prepare nitrate intercalation nickel-aluminum layered double hydroxides in one step. The method is characterized in that an acetic acid-sodium acetate buffer solution is used to stably control the pH of a preparation system to be at 4.00-5.00, nickel nitrate hexahydrate and aluminum nitrate nonahydrate are used as the raw materials, sodiumhydroxide is used as the precipitator, deionized water is used as the solvent and the washing agent, and solution preparation, titration co-precipitation, hydrothermal processing, washing, suction filtration and drying are performed to prepare the nitrate intercalation nickel-aluminum layered double hydroxides. The method has the advantages that influence caused by the fact that CO2 in an environment is dissolved to form CO3<2-> ions can be avoided effectively, and the method is a fast preparation method of the pure-phase nitrate intercalation nickel-aluminum layered double hydroxides.