To meet the needs of foundation bed leveling for the 2nd phase of Yizheng waterway regulation project of the deep-water channel 12.5 m below the Yangtze River of Nanjing,a novel automatic bed leveling system based on ship borne underwater excavator was developed by combining with working conditions on site.This leveling system applied a large-scale barge equipped with automatic leveling excavator and an auxiliary riprap slip cylinder.It was characterized by short construction period,low investment,low cost,the ability of deep-water leveling,safe and reliable technologies,and efficient construction.Additionally,the quality of foundation bed leveling could reach the requirements (±5 cm).