In order to study the influence of MEC non-metallic seal structure on sealing performance and structural strength,taking MEC non-metallic seal of tubing hanger as the research object,by analyzing the structure and principle of the seal,the finite element simulation calculation model of MEC seal was established based on the rigid-flexible contact model and by considering the working pressure,installation method and the internal and external overload of the seal.The influence of each structural parameter of the seal on the sealing performance and structural strength was studied by the single-factor sensitivity analysis method.The results show that when MEC seal works,the overall maximum stress appears at the bending root of metal end cap,and the maximum stress of elastomer appears at the inner contact part.The maximum contact stress distribution shows a gradual decrease from the middle to the two ends,and the changes are approximately symmetrical.The inner length of the sealing ring,the arc radius of the elastomer and the thickness of metal end cap of MEC seal have a great influence on the strength.With the increase of the inner length of the sealing ring,the equivalent stress decreases,and with the increase of the arc radius of the elastomer and the thickness of metal end cap,the equivalent stress increases.The contact surface inclination angle of the metal end cap and arc radius of the elastomer of MEC seal have a great influence on the elastomer contact stress.As the inclined angle increases,the internal and external contact pressure decreases,and with the increase of the inner length of the sealing ring,the internal and external contact pressure increases.The research results provide a reference for the optimization of sealing performance,structural strength and sealing structure of MEC seal.