Abstract: With the development of offshore petroleum industry from shallow sea risers in 1970's to deep sea risers in the 21st century, marine risers have been developed into many types, such as catenary risers, S-shaped risers, etc. As for risers in different mixed transferring systems, the unstable flow, such as severe slug flow, can cause serious equipment damage and thus can have a great impact on production. Therefore, the correct simulation of risers is equally as significant as the proper design, and scientific operation control and elimination of severe slug flow. This paper summarizes the study results in flow simulation of marine mixed transport risers at home and abroad, including the main progress in experimental study, model simulation and software simulation of L-risers and flexible risers. The authors reveal some problems in current study and future study direction, and provide reference to further simulation study in riser flow.