The invention discloses an interface modifying method of a lithium metal battery anode. The surface-modified metal lithium is used for a lithium metal battery. The interface modifying method has the advantages that a solution containing dissimilar metal ions, such as copper, manganese, cobalt, nickel, iron, zinc, gold, silver and platinum, is used as a treatment solution, and a dissimilar metal film is produced at the surface of a lithium piece in situ by a liquid phase chemical replacement method; the dissimilar metal film can be stabilized at the metal lithium/electrolyte surface, the production of lithium dendrites is effectively inhibited, the polarizing of electrochemistry is reduced, the charging property of the lithium metal anode is improved, and the property of the lithium metal battery is improved; the technique is simple, the implementing is easy, the scaled production is easy, and the application prospect is broad.