Abstract: The common plate gate hydraulic discharging device used by Pacific mining company malfunctions frequently. Especially in winter when the malfunction happens， the bin gate is difficult to open. As a result， the materials could not be discharged in time and freeze in the bin. Based on the DEZ-80 plate gate， renovations such as increasing power， adding independently designed small-scale hydraulic station， increasing device motion speed and changing bin gate structure are made， and many tests have been conducted before designing and practicing a new arc dual-opening gate hydraulic discharging device. Field application shows that the device can keep stable and reliable work for 800 h in harsh environment， equipment function rate in winter increases from 89 % to 98.6 %， vehicle loading rate increases from 75 % to 100 %. The number of transportation vehicles is reduced， the parts can be swiftly changed and a maintenance check per month is required， greatly saving maintenance time. The device is worth promotion.