In view of the leakage of the sealing structure of the threeway reversing valve used in slurry shield connector,the sealing characteristics of the rubber seat of threeway reversing valve were studied,and a doublepass sealing structure was adopted to improve the sealing reliability.Twodimensional finite element analysis model of doublechannel sealing structure was established,and the sealing characteristics of rubber doublechannel seal under different lateral medium pressures,different compression and different chamfer radius were compared and analyzed.The results show that the von Mises stress and shear stress of the doublepass sealing structure are in linear relationship with the compression and the lateral medium force.The lateral medium force and the chamfer radius have a greater influence on the contact stress of the first sealing surface.The contact stress on the left side of the sealing surface is relatively high,while the contact stress on the second sealing surface is substantially unchanged.The doublepass sealing structure has the best comprehensive sealing performance at the compression of 2.0 mm and the medium pressure of 1.5 MPa.