The invention discloses a method for preparing a self-leveling floor material from phosphorus solid waste. The method comprises the following steps of: mixing 100 parts of phosphorus slag, 10-12 parts of fly ash, 8-9 parts of cement, 80-90 parts of phosphate tailings, 200-210 parts of pottery sand and 3-4 parts of fiber and stirring uniformly to obtain a solid mixture; adding water into 12-14 parts of activator, 0.3-0.4 part of water reducing agent and 0.2-0.4 part of water preserving agent and mixing uniformly to obtain a liquid mixture; and mixing the solid and liquid mixtures and stirring to obtain the self-leveling floor material. In the invention, the activator activates the phosphorus slag, the fly ash serves as a gelling material, the phosphate tailings replace river sand to be used as an aggregate of the product, the rheological property and mechanical property are sufficiently adjusted by the water reducing agent, the density grade of the material is regulated by the ceramsite, and the absolute dry density can reach 1,100kg/m<3> and even lower. The material is measured according to relevant standards, the indexes completely meet the requirements, the material is light, and the thermal insulation property, breaking strength and cracking resistance are good.