The invention provides a lightweight ceramsite concrete and a preparation method thereof. The lightweight ceramsite concrete comprises, by weight, 200-219 parts of medium sand, 462-470 parts of
cement, 280-316 parts of cobblestones, 110-116 parts of
fly ash, 230-240 parts of super light ceramsite, 230-240 parts of pottery sand, 150-155 parts of water, 8-12 parts of a
calcium aluminum
sulfate expanding agent and 7.0-9.6 parts of a polycarboxylate
superplasticizer. The feeding sequence in the preparation process is changed, sandstones are first added, then
cement,
fly ash and ceramsite are added, and water and additives are added after the ceramsite and other raw materials are fully and uniformly stirred in order to obtain concrete with good workability; and gravity type mixing of a mixer
truck is adopted in the transportation process to prevent the segregation and bleeding phenomena in the transportation process, so the defect of easy segregation of the ceramsite and
cement grout is effectively solved. A ratio of all raw materials is optimized to reduce the
slump, so the ceramsite difficultly floats up to the surface of concrete, and the defect of the easy segregation of the ceramsite and
slurry is avoided.