Bridge-erecting aromatic polyamide composite membranes are suitable for desalination of seawater and high concentration brackish water. It has the characteristics of good and stable desalination performance and low operation and maintenance cost. Especially with the highest desalination rate in the world, it can guarantee the first penetration to obtain beverage water from sea water. By improving the structure of membrane elements, water production can be increased, so the number of membrane elements used can be reduced, and the investment of equipment can be effectively reduced.