Based on the similar characteristics of the stator deformation caused by swelling and thermal expansion,the temperature analogy method was proposed to study the effect of swelling on the sealing performance of rubber stator.The rigidflexible contact finite element model of stator and rotor was established,and the deformation and contact pressure caused by the stator swelling were analyzed.The results show that the contact pressure is increased with the increasing of the swelling ratio when the initial rotor has initially positive interference;under the condition of certain swelling ratio,the stator and rotor can also achieve the seal when the rotor has initially negative interference.