The invention discloses high pumping LC15 ceramsite concrete and a preparation method thereof. The high pumping LC15 ceramsite concrete comprises the following components: cement, sand, ceramsite, mixing water, fly ash, an additive, ore slag powder, a pumping agent and aqueous polyurethane emulsion; the additive is a polycarboxylate superplasticizer, and the pumping agent is compounded by the following components: modified starch ether, polyacrylamide, sodium carboxymethyl cellulose, a retarder, epoxy resin and water. The high pumping LC15 ceramsite concrete enables the ceramsite to fully absorb water, and then through the aqueous polyurethane emulsion and the pumping agent, the bonding of the ceramsite with cementing materials such as the cement, the fly ash and the like is promoted, thecohesiveness and water retention of the ceramsite concrete are increased, and the ceramsite is not easy to float up, delaminate and segregate; and the aqueous polyurethane emulsion is used to adhere an inorganic heat preservation modifier to the ceramsite, and the weight of the ceramsite is increased, so that the ceramsite is not easy to float up, delaminate and segregate, and the heat preservation performance of the ceramsite concrete is improved.