The invention discloses C30 concrete prepared from high-concentration concrete waste slurry water. The C30 concrete comprises the following components in part by weight: 80 to 100 parts of cement, 272 to 292 parts of river sand, 400 to 412 parts of stone, 65.6 to 68 parts of waste slurry water, 30 to 36 parts of coal ash, 37 to 45 parts of mineral powder, 3.8 to 4.6 parts of additive, and 0.92 to 1.04 parts of reinforcing agent, wherein the concentration of the waste slurry water is 10 to 15 percent, the additive is a common water reducer which comprises 1.5 mass percent of plastic retaining agent, and the water-reducing rate of the water reducer is 18 percent. The C30 concrete has the advantages that 1) the reinforcing agent has good functions of preventing the combination of fine aggregate in slurry water and cement, and separating the combined fine aggregate and the cement, the plastic retaining agent added in the additive solves the problems that slumps are reduced quickly due to too high concentration of the slurry water, reduces the water using amount of concrete and guarantees the intensity of the concrete; and 2) the C30 concrete is prepared from 10 to 15 percent of slurry water at the high concentration of 10 to 15 percent, so that the pollution of the high-concentration waste slurry water on environment is reduced, and the utilization rate of the high-concentration concrete waste slurry water is improved.