The Hong Kong-Zhuhai-Macao Bridge(HZMB) project, which has just been opened to traffic in 2018. The special location, construction conditions, quality requirements and multiple functions of HZMB brought many challenges, such as management, technology, safety and environmental protection. To meet these challenges and ensure the achievement of high quality and 120 years design service life, the HZMB project first introduced the completely new concept of "Large size, Factory production, Standardization and Assembly", which was fundamental to the design and construction. This was developed in consideration of the difficulties of the offshore environment.The core idea was Prefabrication and Assembly, which was to change this HZMB project into onshore work as much as possible by cutting this mega sea-crossing into large sized components, which could be prefabricated on land and then transported to the offshore site for assembly. The success of the HZMB undoubtedly has led the technology of prefabrication and assembly to a new height and recognized scale. This paper describes the implementation process of the concept; "Large size, Factory production, Standardization andAssembly" (LFSA) to the HZMB.