The invention discloses a preparation method of a nickel hydroxide composite anode material for an alkaline rechargeable battery. The preparation method comprises the steps: (1) respectively, continuously and dropwise adding a sodium hydroxide water solution, an EDTA water solution and a mixed saline solution into a nickel hydroxide turbid liquid reactor, stirring, separating an obtained product,utilizing deionized water to wash an obtained solid matter, drying to obtain a cobalt and magnesium doped nickel hydroxide active matter; (2) evenly mixing carbon aerogel and cobalt hydroxide with cobalt and magnesium doped nickel hydroxide and nano zinc powder, adding lignin and a polytetrafluoroethylene adhesive and evenly mixing with the defined amount of water to obtain the nickel hydroxide composite anode material. According to the alkaline rechargeable battery nickel hydroxide composite anode material prepared by the preparation method disclosed by the invention, a high energy density iskept, and electrical conductivity and cycling stability are improved at the same time; thus, when the material is applied to the alkaline rechargeable battery, the battery has the advantages of highspecific capacity and longer service life.