During annual maintenance for CDQ system in Anyang Iron & Steel,the coke moisture stays high and fluctuates.In view of the factors influencing the coke moisture,measures were taken such as to standardize coke receiving by quenching car,to control dewatering time and coke discharging on the coke wharf,to optimize quenching time for high and low water volume,as well as to minimize the quenching water volume to maintain the coke moisture around 8% on the premise of no red hot coke so as to ensure stable operation of blast furnace.