To ensure the overall stability of steel cylinders and auxiliary grids after vibration and sinking of the artificial island wall steel cylinders and auxiliary grids of the Hong Kong-Zhuhai-Macao Bridge,we adopt the fixed-point,relay and layered backfilling schemes for the backfilling construction of steel cylinders and auxiliary grids,which can better control the structural safety of the steel cylinder enclosure structure during backfilling construction and prevent the appearance of adverse conditions.Before the enclosure of the artificial island,underwater backfilling is carried out by means of direct dump and pumping.After the enclosure of the artificial island,the land area of the east and west artificial islands of the Hong Kong-Zhuhai-Macao Bridge is quickly formed by means of the scheme of dump and backhaul on the road,which accumulates experience for the quick formation of the offshore artificial island.