Disclosed are a metallic lithium-skeleton carbon composite material having a hydrophobic cladding layer, a preparation method thereof, an electrode, an electrochemical energy storage device containing the metallic lithium-skeleton carbon composite material, and a method for protecting a material containing a water- and oxygen-sensitive active metal. The metallic lithium-skeleton carbon composite material having a hydrophobic cladding layer comprises: a metallic lithium-skeleton carbon composite material comprising a porous carbonaceous support and metallic lithium at least distributed in pores of the porous carbonaceous support; and a hydrophobic cladding layer covering at least the metallic lithium in the metallic lithium-skeleton carbon composite material.