The braking test of the experimental vehicle was conducted, which could indirectly get the braking torque by measuring the bending moment of the braking arm. The braking torque coefficient was obtained by means of the system identification method. Firstly, the relationship between the strain voltage and the braking torque was calibrated. Secondly, the transfer function between the braking pressure and the braking torque was acquired by identifying the collected test data of the experimental vehicle. The experimental results showed that the relationship between the braking pressure and the braking torque of the front and rear wheels could be applied under the different conditions. The gain coefficients obtained from the hydraulic disk brake theoretical model and test model respectively were compared and found in good agreement. However, the test model had the first-order inertia so that it could more exactly express the relationship between the hydraulic pressure and the braking moment of the real vehicle.