The plain river flat slope protection is often damaged at the connecting part of the top and shoal face due to current scouring.Based on Bingyinzhou shoal protection engineering in the middle reach of the Yangtze River and referring to the protection structure,we take spacing-guaranteeing measures at the connecting part of the top and shoal face,where the current speed is relatively large.By generalized fixed-bed and flume experiment,we study the influence of different spacings and heights of the shoal protection on the flow structure and stability of the shoal face and optimize the protection engineering measures.The research results show that in the area of relatively small beach-face velocity,the spacing-guarantee measure is better.