Abstract: With the development of global wind power industry， offshore wind power is gradually expanding into deep sea areas， where traditional jack-up platforms are at risk of being phased out due to their inability to operate in deep water and soft muddy seabed environments. The semi-floating construction method combines the advantages of jack-up platforms and floating platforms， significantly expands the operational depth of jack-up platforms， allows them to continue efficient and safe operations in deep water areas and solves the problem of traditional platforms of inability to work in soft muddy seabed environments. The significance of this technology lies in extending the service life of existing jack-up platforms， avoiding their rapid retirement， and achieving “half a generation later retirement”. Through case studies of offshore wind farms in the coastal areas of Zhejiang Province， a detailed discussion of the principles， key technical steps， and actual engineering applications of semi-floating construction technology is provided， a technical comparison between the semi-floating construction method and traditional construction methods is given， and significant advantages of this technology in improving construction efficiency， reducing costs， and ensuring safety are demonstrated. Finally， this paper looks forward to the broad application prospects of semi-floating construction technology in offshore wind power and other marine engineering.

Key words: semi-floating operation, jack-up platform, offshore wind power, soft muddy seabed, deep sea area construction