The finite element model of rubber C-ring used in the quick-opening blind plate of domestic high-pressure natural gas filter was established.The influences of the seal groove width,internal pressure,initial seal clearance,hardness of materials,notch radius,rim diameter of steel-ring on the sealing performance of rubber C-ring were analyzed by using ABAQUS software,and the reasonable range of these parameters were suggested.The results show that the hardness of materials has little effect on seal performance,while the seal groove width has a certain impact on the sealing reliability,with the sealing groove width increasing,the maximum contact pressure is decreased and the sealing reliability is also decreased.With the increase of internal pressure,the difference between the maximum contact pressure and internal pressure is increased,the sealing reliability is increased.With the increase of initial gap seal,the stress is increased and the sealing reliability is decreased.The sealing notch chamfer radius has large influence on the shear failure of sealing ring,the increasing of chamfer radius will result in large possibility of shear failure.Steelring diameter has large effect on the strain and stress of C-shaped rubber ring,and he increasing of steel-ring diameter will result in the decrease of shear stress.