Hydraulic braking system endow with many merits through the details like rapid reflection, great servo property, braking softly, energy saving, simple structure, easy maintenance and low cost, and so on. The train hydraulic braking test system was designed and established in order to test the possibility of using the hydraulic technology to brake high speed trains. The sport state was analyzed about the process of the braking of the test system by using the software of MATLAB/SIMULINK. Curves on the relation of time and braking distances under different braking forces are obtained.