Abstract: Disclosed is a method for preparing bittern-carbonization synergistic reinforced recycled aggregate, including the following steps: spray pretreatment: performing alternate spraying on recycled aggregate with bittern and lime milk at intervals for many times at 4-70° C. and a pressure of 0.05-0.6 MPa; carbonization reinforcement: introducing waste gas containing carbon dioxide for a retention time of 4-8 h after the recycled aggregate is allowed to stand for 2-4 h; and rinsing and air drying: removing soluble impurities on a surface of the recycled aggregate by rinsing in water, and performing air-drying on the recycled aggregate to obtain bittern-carbonization synergistic reinforced recycled aggregate. According to the present disclosure, the effective reinforcement of recycled aggregate at normal temperature and pressure in a short time is realized, and the method is simple in process and is convenient in operation.