Abstract: The indoor flume experiment is an important means to study the geological deposition process and its evolutionary regularity, and how to measure the change of geological body in the deposition process accurately is a key link in this kind of simulation experiment. In this paper, the main components and key technologies of the newly developed real-time imaging system of 3D ultrasonic seismic model are introduced. This system is used to simulate marine earthquakes, and can obtain dynamic images of multi-layer complex geological models by rapid measurements and the real-time data migration and imaging after deposition experiments, therefore, the experimental efficiency and imaging accuracy is greatly improved. The system has good real-time performance, imaging quality and detection range, and has broad application prospects in the researches on geological deposition, marine geology and three-dimensional seismic model.