To reveal vibration characteristics of hydraulic excitation system based on the fluid-filled pipe, a hydraulic excitation testing system is developed, which mainly consist of an elastic plate connected with the pipe served as a vibrating unit. Its mathematical model is established, the evolutionary process of the three-dimensional and two-dimensional vibration trajectories is simulated. By comparison, the vibration trajectories of the two-dimensional vibrating screen are regular, and that of the three-dimensional vibrating screen is confused, but which has higher screening efficiency. So, served as a new vibration mode, the three-dimensional vibration trajectory based on the hydraulic excitation has more advantages than that of the two-dimensional. [ABSTRACT FROM AUTHOR]