Abstract: The original whole section wedge broken belt catch device is improved and the broken belt catch system driven by hydraulic motor is applied and designed, its working principle is introduced. The simulation model of hydraulic system is established and the system is simulated based on the hydraulic simulation software AMESIM. The relation between key parameters and dynamic response of system is researched. The results show that the response of the upper wedge broken belt catch mechanism increases and then decreases with the increase of hydraulic motor displacement; the response decreases with the increase of hydraulic motor rated speed and the response increases with the increase of cartridge valve diameter, the bag volume and the charged pressure of accumulator.