The fine sediment in the channel often forms the turbidity maximum zone,which moves back and forth under the two-way action of the runoff and the tidal current，and develops into fluid mud at the bottom of the channel.The movement laws of flow and sediment are extremely complicated.In recent years,human activities in the estuary become more frequent.In particular,the estuary reclamation has caused big changes in the hydrodynamic and boundary conditions of the estuary.Moreover,the construction of upstream reservoir has reduced the runoff and peak discharge,in combination with the jacking function of tidal water,resulting in siltation in the channel and turbid river water.Taking the Jiao (Ling) River as an example,this paper analyzes the characteristics of flow and sediment in mountainous river with strong tide based on the measured data and considering the effect of sediment transport characteristics of viscous fine grain and salinity,develops the mathematic model of the maximum turbid zone movement in the mountainous river,and simulates the transport characteristics of the turbidity zone in the Jiao (Ling) River.