Abstract: Multi-phase flow transportation is an important aspect in the development of present pipeline transportation technology. Evident characteristics of multi - phase flow technology in the aspect of reducing pipeline transportation investment and operation cost has made it more and more applicable for oil & gas transportation. In the development of offshore oil & gas fields, in order to simplify platform treatment process, reduce pipeline investment, multi-phase flow transportation has been adopted in most oil & gas gathering pipe networks and long distance condensate transportation. The article, combined with the application of multi-phase flow technology in present offshore oil & gas transportation, discusses a major aspect of this technology.