The invention belongs to the field of preparation of composite performance materials, and provides a preparation method of high-density anisotropic conductive metalized wood, which comprises the following steps: pretreating a wood fiber structure; carrying out vacuum infiltration on metal liquid in a wood fiber channel; and carrying out surface treatment on the metalized wood. In the pretreatmentstep, lignin in a log fiber structure is washed away without destroying the fiber structure by adopting a mixed solvent of dilute ammonia water and an alkali metal halide aqueous solution, a good fiber channel is provided for permeation of molten metal, and meanwhile, nano halide molten salt particles precipitated from the wood fiber structure can achieve a flame retardant effect at a high temperature; the permeated metal is an alloy material, the metal is melt into a liquid state in a constant-temperature vacuum oven, then wood to be permeated is soaked into the molten metal, and permeation is carried out under a vacuum condition; and after the permeation is completed, the surface of the metalized wood finishing the permeation is polished through mechanical polishing equipment, and thus the large-density anisotropic metalized wood with a uniform surface and a good state is obtained.