In order to improve the sealing performance of rubber core of rotating control head in the process of drilling with pressure,the finite element governing equation of dynamic sealing process was obtained based on the virtual work principle,and the Yeoh constitutive model in rubber core deformation process was established by uniaxial compression tests.The three-dimensional finite element model of rubber core was established by using ABAQUS experimental platform.By simulating the dynamic sealing process of rubber core in the process of drilling with pressure,the force distribution on the mechanical seal face was obtained.The influence of the structural parameters such as such as inner cone angle,outer cone angle and inner diameter of rubber core on the sealing performance of the drill pipe were studied.The results show that the contact pressure of the main sealing surface of the rubber core is greater than that of other parts,and the contact pressure at the inflection point between the main sealing surface and the inner conical surface is the largest.The contact pressure of inner cone surface increases when the inner cone angle increases,the contact pressure of sealing surface fluctuates when the outer cone angle increases,and the contact pressure of main sealing surface decreases when the inner diameter increases.The structural parameters are optimized by orthogonal test.It is concluded that the optimal combination of structural parameters is inner cone angle of 24°,outer cone angle of 64° and inner diameter of 79 mm of the rubber core.The peak contact pressure of the optimized scheme is reduced by 0.51 MPa and the Mises stress amplitude is decreased by 57.5%.The field application shows that the fatigue life of the rubber core is significantly increased under the premise of meeting the requirements of the rubber core seal,which verifies the accuracy of the finite element simulation analysis.