In order to explore the suitable seals between seed bins and cylinder for supercritical CO2 continuous extraction,two-dimensional symmetrical models of O-ring,Y-ring,and U-cup-ring were established by using ANSYS software.The contact stress and equivalent stress of seals under the influence of compression and friction coefficient in the pushing process and the best push form of seals,as well as the stress distribution and change law of seals under pressure were analyzed.The results show that in the pushing process,the O-ring has better pre-tightening sealing performance,and the equivalent stress of the U-cup-ring is the smallest and the stress distribution is uniform.With the increase of compression and friction coefficient,the stress changes of the O-and Y-rings will fluctuate,while the stress of U-cup-ring will maintain linear growth.Under pressure working condition,the sealing performance of Y-ring and U-cup-ring is better than that of O-ring.The sealing performance of the Y-ring is the best under high pressure,but its bottom of low lip is prone to shear failure,which affects its service life.The sealing performance of U-cup-ring is the most stable and reliable under high pressure.