A method for determining the width of the excavation groove is proposed based on the relationship between the river facies and the maximum sediment transport rate of the pebble river.Taking Dongxikou waterway regulation in the upper reaches of the Yangtze river as an example,Einstein’s formal and flexible sediment transport rate formulas are used to calculate the width range of the excavation groove corresponding to the maximum sediment transport rate at the remediation water level,and the stable river width is calculated by using the method of river relationship.The results show that the width ranges of stable excavation groove determined by the two methods are basically the same.The optimal size of Dongxikou channel is determined by optimizing the section design of the excavation groove through mathematical model,which can meet the requirements of stability of the gravel channel and ship navigation.