The invention relates to a tobacco purple mud rock floating seedling matrix material, belonging to the technical field of flue-cured tobacco seedling. The tobacco purple mud rock floating seedling matrix material comprises 80% of purple mud rock, 10% of organic fertilizer and 10% of expanded perlite according to the volume ratio, wherein the purple mud rock is granular material, and is formed by mixing the components by volume ratio: 65-80% of 2-4mm purple mud rock granules and 20-35% of 4-6mm purple mud rock granules. Compared with the prior art, the tobacco purple mud rock floating seedling matrix material has the advantages of low cost, convenient material taking, low-carbon eco-environmental protection, being labor-saving, high in survival rate and vigorous in tobacco seedling tall stem. The practical application proves that the cost of per acre purple mud rock floating seedling matrix material is 7.85 yuan which is only 1/3 of that of grass peat commercial matrix; and the utilization rate of the fertilizer is improved, and salting-out phenomenon is reduced.