Abstract: Taking the double-cone seal structure as an example, the compress and resilience mechanical behaviors of gasket were simulated using multiple kinematic hardening model, and the cooling rate and pre-tightening load on the effect of contacting pressure of gasket sealing surface were explored. Also, the sealing characteristic of this structure was scientifically expressed based on leakage model, and the design method considering the maximum allowable leakage criterion was founded. Leakage problems based on ASME and GB-150 specification were successfully solved. It will provide technical support for bolted-flange-gasket connection sealing in industrial design.