The utility model provides a metal seal steel ring of linear sealing, the metal seal steel ring is circular ring shaped structure, the sealing surface that is the metal seal steel ring between outer anchor ring of doughnut -shaped structure and the terminal surface, the transversal arc of personally submitting of sealing surface. Metal seal steel ring outer loop cross section middle part is followed the central line position and is equipped with the round recess. When the contact of metal seal steel ring and flange when compressing tightly, the sealed cambered surface of metal seal steel ring be the line contact with the contact of flange seal face, under equal effort, the elastic deformation that the elastic deformation of steel ring and flange line contact compared traditional face -contact is bigger, its sealed effect is more outstanding with the effect, more can overcome sealing surface roughness and processing technology's drawback, the effect is sealed up in the connection that also can keep better when just carrying out wiper seal experiment and moment of flexure loading test.