Judging from the actual situation for many years，the scour and deposition of the reach of the Yangtze River from Yibin to Chongqing is relatively balanced，and the replenishment of sand and gravel is very small and slow compared with sand mining. So it is bound to cause longitudinal and lateral deformation of the riverbed，thus changing the river regime and causing changes in the flow conditions of the waterway. Based on the measured data，the characteristic parameters of the beach failure zone in the reach of the Yangtze River from Yibin to Chongqing are obtained. Through mathematical model calculation，and combined with the measured topography and water level data of typical beach dangers，the analysis shows that：the current disorderly sand mining pits have reduced the water level to a certain extent near the Zengbingqi river section and part of the navigating water gauge during the dry season，which has brought some difficulties to the waterway maintenance department and ship navigation. This issue needs to be studied and paid attention to.