High-fluidity high-strength gypsum-based sand-free self-leveling mortar as well as preparation method and application thereof

The invention discloses a high-strength gypsum-based sand-free self-leveling mortar with strong fluidity. The mortar is prepared from the following raw materials in parts by weight: 400-920 parts of phosphogypsum powder, 80-600 parts of a modified filler and 5-12 parts of an additive, the phosphogypsum powder is one of phosphorus building gypsum powder, mixed-phase gypsum and alpha-type high-strength gypsum. The high-strength gypsum-based sand-free self-leveling mortar disclosed by the invention is good in flowing property and relatively low in cost, the advantages of self-leveling of sand-free gypsum and sand self-leveling can be fully exerted, and the effects that the sand self-leveling mortar is not easy to crack, hollowing, dusting and'bleaching black 'and is high in strength can be achieved; the sand-free self-leveling mortar has the advantages of good construction flowing property and low cost, and has the advantages of no cracking, no hollowing, no dusting, no bleaching black, strong binding power and