Generalized model test was performed to study the effect of beach protection belt at Lalin sandbar in Taipingkou waterway of Jingjiang River in the middle Yangtze River. Result demonstrates that the beach protection belt project plays a good role in flow control and enhances the stability of Lalin sandbar. The project restores the middle segment of the Lalin sandbar, giving rise to a good flow diversion effect and intensifying the flow connection from the south trough to the north branch, and therefore ameliorates the navigation channel from the outlet of Taipingkou to Sanba sandbar. The research result offers technical support for the navigation channel regulation project at Taipingkou waterway.