In order to keep device operation safely,stably and chronically,by means of condition adjustment and system optimization in the actual operation,the effects of valves and other equipment fault,the upstream and downstream system fluctuation etc. on the balance of gasifier pressure,steam drum pressure,nitrogen/carbon dioxide pressure and pulverized coal flow were discussed.The imbalance harm to production was analyzed,a method to maintain the balance was summarized.It was pointed out that keeping these key parameters balance had the significance to the good operations of Shell coal gasification plants.