Overwater and underwater three-dimensional real-time construction system and method for dredger

The invention discloses a dredger overwater and underwater three-dimensional real-time construction system, which comprises a signal acquisition module, a data transmission module, an overwater scene rendering module, a ship structure module and an underwater terrain real-time construction system, and is characterized in that an original water area establishment module comprises a beam sounding unit, a receiving transducer array and an algorithm operation unit; and an original terrain construction unit. The module is used for measuring the seabed water depth and constructing an original terrain curved surface according to a measurement result; the rake head model building module is used for building a rake head model; the collision detection module detects intersection coordinates of working coordinates of the rake head and original terrain coordinates; and the terrain reconstruction module is used for obtaining a new terrain curved surface. The underwater dredging effect is displayed in real time, meanwhile,