Penalty function method was used to introduce the constraints of contact surface into potential energy function,finite element analysis equation was established and solved numerically by the Newmark method,the effects of geometry and physical parameters of packer's rubber on packers rubber sealing properties were analyzed.The results show that the maximum contact pressure between rubber and casing is increased along with the increasing of rubber length,and the increase of contact pressure is slowed down when rubber length reaches a certain value.The maximum contact pressure between rubber and casing is increased and compression thickness is decreased gradually along with the increasing of rubber width.A larger material coefficient should be chosen when designing material parameters to meet the sealing requirements.