To explore the water depth resources of the channel in Chenglingji to Wuhan reach，the study section is divided according to the river phase relationship parameters of each channel.The maximum stable channel depths of the channels in different sections are calculated by the stable channel depth estimation method to determine the maximum water depth of the channel in the study section.The results show that the study section is based on the change rule of the river phase relationship parameters of the channel，it can be divided into three sections from upstream to downstream，such as Xianfeng waterway to Xindi waterway，Shitouguan waterway to Paizhou waterway，and Shuihongkou waterway to Baishazhou waterway.The maximum stable water depths of the channels under 98% design navigation guarantee rate and 200 m navigation width of the three sections are 6.133 m，11.268 m and 6.433 m respectively from upstream to downstream，so the maximum stable channel depth of Chenglingji to Wuhan reach under 200m planned channel width is 6.1m.