In order to improve the reliability and life of adaptive large flow safety valve key parts, UG software was used to establish the 3D model of the adaptive large flow safety valve key parts, and with the help of ANSYS Fluent software, through unidirectional fluid-structure coupling analysis, the stress and strain cloud diagrams of the key parts such as first stage cone valve and second stage differential valve core were obtained. In order to further study the low pressure sealing performance of the adaptive large flow safety valve, the pressure test of ZF-2WG hydraulic support valve was carried out at 6 MPa and 14 MPa. The simulation and experimental results show that the stress concentration region is near the cone surface of the first stage cone valve, and the strain concentration region is near the cone tip. The outlet of the four damping holes on the side of the differential cavity of the secondary valve core is the stress concentration area, and the fluid contact area of the external annular differential cavity of the secondary spool is the strain concentration area. When the P port pressure is 6 MPa and 14 MPa, the pressure holding time is 120 s, the pressure value is basically maintained at the set value, the pressure holding effect is very ideal.