The invention provides high-strength high-water-storage concrete and a preparation method thereof; the concrete includes raw materials composed of cement, an admixture, fine ground quick lime and gypsum and has addition of a water reducer and an early strength agent; the cement, admixture, quick lime and gypsum respectively account for 40%, 40%, 15% and 5% of the raw materials; the externally mixing ratios of the water reducer and the early strength agent are both 1% of the raw materials; the admixture can optimize the mix proportion to increase the strength of the concrete and reduce the drying shrinkage value. Due to good water storage and water and gas permeability, moisture accumulated in the high-water-storage concrete is evaporated, the heat island effect is reduced, and the high-strength high-water-storage concrete has the characteristics of water storage, water permeability, gas permeability, light weight and the like.