Aiming at the urgent demand for large-diameter high-temperature resistant metal seals in the industrial field,a large ring diameter ratio of O-shaped composite metal seals was developed,in which a spiral mesh metal rubber formed by cross-wound hooks is embedded in a thin stainless steel ring with a certain opening groove.The preparation process of O-shaped composite metal seals with a large ring diameter ratio was explored,including the preparation process of metal rubber elastic inner core and stainless steel cladding layer.The mechanical properties of four different porosity metal rubber seals at quasi-static room temperature were studied,and the influence of load and porosity on the mechanical properties of metal rubber seals was analyzed.The results show that the composite metal rubber seal has good sealing performance under high load,and the mechanical properties of the seal tend to be more stable when the load increases.And with the decrease of porosity,the bearing capacity becomes larger and larger.Based on the static performance test,a polynomial fitting function for metal rubber seals with stainless steel coating was established.It is found that the sixth-order polynomial can fit the test data well,so that the static stiffness of the metal rubber seals can be calculated and analyzed.The law of change between and displacement can be better applied in engineering.