Much attention has been paid to the synthesis of porous materials, but many of the proposed methods are limited by toxic, expensive solvents, high-pressure reactor, and so on. Herein, a simple direct calcining solution approach was established to synthesize porous Co3O4/C/(Mg, Ca)O nanocomposites by natural biological template. The composition, morphology, phase structure, surface element composition, porosity and specific surface area of Co3O4/C/(Mg, Ca)O nanocomposites are investigated. The Co3O4/C/(Mg, Ca)O nanocomposites presented porous structures and keep the original features of natural biological template. Based on a series of contrast experiments, the possible growth mechanism and fabrication process of the products have been proposed. For dynamic damping absorption applications, it was demonstrated that the nature rubber composites with 40 phr porous Co3O4/C/(Mg, Ca)O showed efficient damping absorption (E″>2.5 MPa) in the broad frequency of 33.1–92.1 Hz with low loss factor. The superior damping absorption properties indicate that the as-prepared Co3O4/C/(Mg, Ca)O composites have potential application as candidates for damping absorption. More importantly, this simple approach offers a potential way to prepare porous metal oxide/carbon composites from natural biological templates.