The invention relates to the technical field of regenerated bricks, and discloses a construction waste regenerated brick which comprises the following raw materials in parts by weight: 30-45 parts of cement, 65-80 parts of fine aggregate, 55-70 parts of recycled brick coarse aggregate, 1-5 parts of polypropylene fibers, 10-20 parts of kaolin, 30-50 parts of fly ash, 1-5 parts of a water reducing agent, 1-5 parts of an early strength agent, 1-5 parts of an anti-freezing agent and 15-25 parts of water. The invention further relates to a preparation method of the construction waste regenerated brick, which comprises the steps of 1) preparing cement, fine aggregate, regenerated brick coarse aggregate, polypropylene fibers, kaolin, fly ash, a water reducing agent, an early strength agent, an anti-freezing agent and water, pre-wetting a barrel of a stirrer, then putting the regenerated brick coarse aggregate, the cement and the fine aggregate into the stirrer, pre-stirring for 2-3 minutes, uniformly stirring to obtain a mixture for later use, uniformly dispersing the polypropylene fibers into the obtained mixture, and carrying out dry mixing for 1-2 minutes to obtain mixed powder. According to the construction waste regenerated brick and the preparation method thereof, the purpose of higher strength is achieved.