Abstract: Disclosed is a method for preparing high-strength coral aggregate concrete under low pressure conditions, including the following steps: weighing cement, mineral admixture, coral aggregate, mixing water, water reducer, and defoamer; mixing the cement and the mineral admixture well to obtain a cementing material; putting the coral aggregate, sea water, water reducer, defoamer, and 55-85% of the cementing material into a closed mixing system to stir for 10-15 min under low pressure conditions, and pouring the remaining cementing material into the mixing system to stir for additional 10-15 min to prepare the high-strength coral aggregate concrete. The high-strength coral aggregate concrete obtained has advantages of high mechanical properties, high compactness, excellent impermeability and durability, drawing on local resources in construction engineering on remote islands and reefs, and maximum resource utilization.