Aiming at the working performance of steam turbine under hydrogen-rich fuel，a refined parameter model of steam turbine was established by combining thermodynamic mechanism with actual operation data by using dual-drive method. The correction coefficient of the velocity loss coefficient of the first-stage stator blade of the steam turbine was proposed to consider the cooling effect，and an alternative model was constructed for the thermal calculation process of the first-stage stator blade of the steam turbine. At the same time，the influence of hydrogen-rich fuel on the flow matching between compressor and steam turbine under off-design conditions and the adjustment of operating parameters and structural parameters were studied. The results show that with the increase of hydrogen volume fraction in the range of 0~18%，the electric power increases and the total efficiency decreases. When the hydrogen volume fraction exceeds 18%，both the electric power and the total efficiency decrease. The research shows that the proposed steam turbine modeling method has good reliability and accuracy.