Abstract: The Damazhou waterway is a slightly meandering channel in the middle reaches of the Yangtze River, abutting on Yaojian bifurcation stream. For frequent translocation of the primary flow outflowing from the Jianli waterway, it directly leads to the instability of the primary flow along the Damazhou waterway and the position of the shoal, and to the change of deep channel. And there is a navigation hindering phenomenon of the meandering inflow section and wide-shallow outflow section. The design scheme is focused on the bank revetment of the Binyinzhou and Damazhou floodplain, and it is not enough to maintain the river regime and waterway stability during the low flow season. Some measures should be taken to stabilize the favorable river regime again when the “shape of S” of the Damazhou waterway evolves into a single meandering channel. Through local movable-bed model tests, different scheme studies on the design width of the bottom-protection mattress and the floodplain protection effects for the Binyinzhou shoal have been carried out. The analysis results show that the bottom protection effects of the preliminary design scheme are better than those of the recommended design scheme of the feasibility studies thanks to the frontage of the bottom protection mattress placed closer to the main channel. As for the considerable erosion along the surface of the upper section of the Damazhou floodplain where the velocity is higher than 0.8 m/s in the major flood period, it is necessary to take some appropriate measures for the shoal protection works.