Concrete, preparation method thereof and 3D printing material

The invention discloses concrete, a preparation method thereof and a 3D printing material, and belongs to the technical field of concrete materials. The concrete comprises a dry mixture and water in a mass ratio of (2-5): 1; the dry blend comprises the following components in parts by mass: 10-20 parts of a solid waste-based mineral admixture, 55-75 parts of Portland cement, 5-15 parts of sulphoaluminate cement, 70-100 parts of quartz sand, 5-15 parts of an expanding agent, 0.4-0.8 part of an early strength agent, 10-15 parts of silica fume and a reinforcing additive. The reinforcing additive is prepared from at least one of 0.6 to 0.9 part of manganese ion doped calcite type nano calcium carbonate and/or 0.5 to 0.7 part of composite fiber. The composite fibers comprise titanium dioxide nanofibers, PP fibers, alumina fibers and polyamide 66 fibers in a mass ratio of 1: (5-10): (5-10): (8-15). The reinforcing additive is beneficial to improving the strength, toughness and interlayer binding force of the concre