Abstract: In order to guarantee safe and smooth operation of plug in the plugging process and reduce the occurrence of plug plugging caused by internal hindered turbulence, based on fluid dynamics, different plugging states of internal plug were simulated using Fluent software. And as a result, the change laws and force situations of flow fields around the plug at different plugging situations were understood. And finally, simulation results were compared between the simplified model and the actual model, and the impact of the contour of support wheels on flow fields was analyzed. Results show that the pressure increases significantly and the flow is smoother at the upstream of plug. At the downstream, turbulence appears with swirls of different dimensions. The research findings play an instructive role in the shape design of plug and the safety of plugging operation.