The seal performance of the adjustable and controllable reciprocating seal device under high pressure was analyzed by ABAQUS software,the stress distribution and deformation of the seal assembly and the traction rope were obtained.The influence of the control pressure and the medium pressure on the seal leakage rate and the friction force was analyzed.The main seal test device was designed and built for test verification.The results show that reasonable control pressure and sealing structure design can achieve better contact stress distribution and significantly reduce seal leakage.With the continuous increase of the control pressure,the seal leakage first drops rapidly,and then drops slowly and gradually becomes stable.When the control pressure is greater than 1.3 times of the medium pressure,the leakage rate is close to zero.Increasing the control pressure leads to a slow and then rapid growth trend of friction force.The media pressure has an opening effect on the sealing ring,which can reduce the fluid film pressure and thus reduce the friction force.In engineering applications,the best sealing effect is achieved when the control pressure is 0.2 to 0.5 MPa higher than the medium pressure