In order to prevent the cage falling accident caused by the breakage of lifting wire rope in fully mechanized mining transportation equipment, a safe and reliable normally closed drop preventer was designed, and the performance of the hydraulic control system was analyzed in detail. The normally closed hydraulic drop preventer system model was established by using AMESim software, and the braking distance curve, braking speed curve and flow characteristic curve of the braking hydraulic cylinder were obtained through simulation under the input signal instruction, and the factory test of the drop preventer was carried out. The results show that the system meets the design requirements and can work safely and reliably.