Diamond drill bit for large-diameter drilling construction

The invention relates to the technical field of diamond drill bits, and discloses a diamond drill bit for large-diameter drilling construction. A threaded groove is formed in a drill bit body; a drilling component is mounted on the upper part of the drill bit body; limiting rods are fixedly connected to the lower surface of the drill bit body along the annular face of the drill bit body in an equally spaced mode; limiting grooves are formed in the upper surface of a drill rod along the annular face of the drill rod in an equally spaced mode, and a fastening component is further mounted betweenthe drill bit body and the drill rod. According to the diamond drill bit for large-diameter drilling construction, through the drilling component, stratum rock can be preliminarily drilled, so that the rock cracks to be beneficial for reducing the subsequent wearing degree of a cutting block; and moreover, the cutting block can cut the rock more conveniently, so that the drilling efficiency is greatly enhanced; and throu