Concrete cracks are likely to occur at floor,chamber wall,top and side wall of water delivery gallery,top and side surface of the threshold and other parts of the lock.Through theoretical analysis and field practices,the design,materials,construction methods are proposed,including adjustment of rebar diameter and rebar spacing,setting wind construction joints,adjustment of the cooling water pipes,optimization of concrete mix,using whole section pouring process,control the layered pouring interval.The good effect is obtained.