Abstract: According to contacting mechanical seals, three dimensional steady state mechanics model is established including axial mode and angular modes. Taking account of contacting effect between seal rings’ faces and liquid cavitation, a mathematical computational method is proposed. Influence of initial rotor misalignment, stator coning angle on relative nutation angle between rings is analyzed. Leakage rate, distribution of film thickness, liquid pressure and contact pressure in steady state is computed. Results show that initial rotor misalignment and face coning angle have a great effect on seal performance. Mathematical model and computational method can be used to analyze seal performance and to guide the optimization design of contacting mechanical seals.