The invention belongs to the technical field of fiber materials, and particularly relates to a compound carbon-fiber material prepared by taking biomass tar, nano-silver and PAN as materials, and a preparation method of the compound carbon-fiber material. By taking the biomass tar, the nano-silver and the PAN as the materials, the compound carbon-fiber material is prepared by means of electrostatic spinning, thermal stabilization and carbonization processes in sequence, and has antibacterial property. The biomass tar/nano-silver/PAN compound carbon-fiber material provided by the invention is a better porous CNFs(carbon nanofibers), and compared with traditional wet spinning, the preparation method is simpler, and the specific surface area is greater; the prepared compound material is provided with nano-silver particles by creatively adding a silver ion material and performing reduction treatment, the antibacterial property of the compound carbon-fiber material is enhanced, and the application prospect is wider; meanwhile, new possibility is provided for recycling, development and utilization of the biomass tar.