Abstract: In order to effectively absorb impact existed in broken belt catch process of downward belt conveyor, a hydraulic buffer system of broken belt catch for downward belt conveyor was proposed. Working principle of the system was analyzed, and a simulation model of the system was established based on AMESim. The influences of opening pressure of relief valve, diameter and length of hydraulic hose, bladder volume and charge pressure of accumulator on displacement and rod cavity pressure of hydraulic cylinder were simulated and analyzed. The simulation results show that the larger the opening pressure of relief valve is, the smaller the displacement of hydraulic cylinder is, and the larger the rod cavity pressure peak of hydraulic cylinder is. The larger the hydraulic hose diameter is, the larger the displacement of hydraulic cylinder is, and the smaller the rod cavity pressure peak of hydraulic cylinder is. However, the influence of hydraulic hose diameter on displacement of hydraulic cylinder decreases when hydraulic hose diameter increases to a certain value. The longer the hydraulic hose is, the smaller the displacement and rod cavity pressure peak of hydraulic cylinder are. The larger the accumulator bladder volume is, the smaller the displacement of hydraulic cylinder is, and rod cavity pressure peak of hydraulic cylinder is unchanged. The larger the accumulator charge pressure is, the larger the displacement of hydraulic cylinder is, and rod cavity pressure peak of hydraulic cylinder is basically unchanged.