The invention relates to the technical field of fiberboards, in particular to a waste fabric fiberboard. The fiberboard comprises, by weight, 20-35 parts of waste fabric fibers, 15-20 parts of crop straw fibers, 20-30 parts of waste pulp fibers, 20-30 parts of wood fibers, 5-8 parts of imvite, 5-8 parts of a diatomite-fire retardant composite material, 3-5 parts of activated carbon, 3-5 parts of anegative ion sustained-release agent, 5-10 parts of a fire retardant, 2-5 parts of biomass lignin glue, 1-3 parts of a waterproofing agent and 0.5-1.5 parts of a PPE wet strength agent. According tothe waste fabric fiberboard, the waste fabric and waste pulp are used as raw materials, the raw materials are easily obtained, waste is utilized, the materials are saved, the production cost is reduced, the pollution of the waste fabric and waste paper to the environment is reduced, and the economic and social benefits are high.