Nickel formate, also known as nickel formic acid, is a green monoclinic crystal or crystalline powder with a relative density of 2.154. When it is carefully heated to 130~140 ℃, it becomes anhydrous salt. It is decomposed into nickel, carbon monoxide, carbon dioxide, hydrogen, water and methane at 180~200 ℃. Soluble in water. It is prepared by the reaction of nickel sulfate solution with sodium formate or nickel hydroxide dissolved in formic acid. Used for manufacturing nickel and nickel catalyst, etc.