A new ODE model is proposed for severe slugging flow in pipeline-riser systems. Severe slug characteristics predicted by the proposed model are compared to laboratory data and control feature of severe slugging flow is compared to the result from OLGA® simulator. For the valve opening of 100% (without control), the characteristics of severe slugging flow including severe slug period, pressure fluctuation limits show good agreement with the experimental data. For the valve openings of 9%, 8%, 7% (choking), as predicted by the new model, severe slugging is gradually transformed to a stable non-oscillation flow regime, which is approximately in accordance with the results of OLGA® simulator. As the proposed model is based on simple ordinary differential equations (ODE), the calculation speed of the new model is much faster than OLGA® simulator, better for real-time severe slugging control.