Diaokouhe is the spare river route of the Yellow River hereafter called YR at that estuary.The combined operating plans of Qingshuigou and Diaokouhe are studied in this paper, and several plans are put forward:(1)Begin to use Diaokouhe after Qingshougou is completed, (2)plan for combination use of Qingshuigous three routes and Diaokouhe;(3)use Diaokouhe as a flood by-bass at the case of high water level;(4)use Diaokouhe for ecological water transfer;(5) use two rivers at the same time.The defence water level in Xihekou station 1s 12 0 meter(elevation of Dagu system)when the discharge is 10000 m3/s, it was 10.37 meter in 2011 at this discharge, and the dikes of YR lower reaches defence water level is based on this standard.Owning to the much useful volumn of Qingshuigou, it is not urgent to make Diaokouhe as a flood by-bass at present by plan chosen.Using Diaokouhe for ecological water transfer is remmonded in this paper.Not only the ecological worsen of national natural reserve in the northern zone of YR estuary is restrained, but also the spare routes water transportation is maintained by adopting this plan.