To meet the demand of short-distance arresting for high-speed sled in impact safety test,a new arresting system was introduced based on damp buffer water cylinder and flexible arresting rope with high-strength.According to the structure and working mechanism of this arresting system,the dynamic models were established,taking into account the elastic deformation of the arresting rope as well as the inertia effect of the piston.The characteristics of key dynamic parameters such as acceleration,water pressure,arresting distance were obtained by the dynamic models,and they were verified with the test data.It was proved that the established dynamic model can accurately reflect the dynamic characteristics of the arresting system.Based on the dynamic models,the influences of rope stiffness,damp hole distribution forms,damp hole areas,piston mass on the arresting performance were analyzed.Some conclusions can be obtained.It is advisable to choose light and high-strength flexible arresting rope.The damping effect of water cylinder is better when the distribution of damp holes with high slope hyperbolic line is selected.The damp hole area and piston area should be evaluated comprehensively during design.On the premise of ensuring the structural strength of the piston,the mass of the piston should be reduced as far as possible.