The invention belongs to the technical field of metal anode oxidation and particularly relates to a steel anode oxidation electrolyte solution and an anode oxidation method thereof. The electrolyte solution comprises 0.2-1 mol/L of citric acid, 0.01-0.15 mol/L of ammonium fluoride, 0.01-1 g/L of glycerin, 0.01-1 g/L of alkylphenol polyoxyethylene and water. The anode oxidation method comprises thesteps of polishing, burnishing and washing the surface of a steel workpiece, adopting the steel workpiece as an anode, adopting a graphite plate or a lead plate as a cathode, utilizing the electrolyte solution to carry out anode oxidation treatment, and enabling a layer of oxidation film to be generated on the surface of the steel workpiece. Surface oxide obtained through the steel anode oxidation electrolyte solution and the anode oxidation method has the advantages of being high in combination force, resistant to wear and resistant to corrosion, and the problem that in the prior art, anodeoxidation treatment cannot be carried out on steel easily.