In view of the shortcomings that the rubber packer is difficult to adapt to the working conditions above 150 ℃ and 70 MPa,a metal packer with W-shaped sealing structure was designed,which was suitable for the working conditions of 230 ℃ and 70 MPa,with load transmission at both ends and a hollow in the middle to promote radial deformation,and its sealing performance was studied.According to the requirements of working conditions,β-NiTi alloy was selected as the W-shaped sealing structural material based on the temperature-dependent and superelastic transformation stress,the sealing performance of the W-shaped structure was evaluated by the contact stress generated after setting,and the unsetting performance was evaluated by the elastic-superelastic strain rate of the W-shaped structure under working pressure.The effects of the size radius,wall thickness and wall thickness ratio of the W-shaped sealing structure on its sealing performance were analyzed.The results show that the size radius has little effect on the sealing performance and unsetting performance of the W-shaped sealing structure,while the wall thickness and wall thickness ratio significantly affects the sealing and unsetting performance.With the increase of wall thickness,the sealing performance of the W-shaped sealing structure gradually decreases,but the unsetting performance gradually increases.With the increase of the wall thickness ratio,the sealing performance gradually decreases,and the unsetting performance first increases and then decreases.The sealing performance of the optimized W-shaped structure was simulated and analyzed.It is found that the W-shaped sealing structure metal packer with β-NiTi alloy material can be fully applied to the high temperature and high pressure environment.Under the working conditions of 230 ℃ and 70 MPa,the load required for the structural setting is 220 kN,and the elastic-superelastic strain rate is more than 90%.