The thermal deformation behavior of 1Cr10Co6MoVNbN stainless steel under the temperature of 800-1100 ℃ and the strain rate of 0.01-10 s-1 was studied by thermal simulation experimental machine Gleeble-3500, and the stress-strain curve was obtained. Then, the constitutive equation was constructed, and the influences of temperature, strain rate and deformation amount on its microstructure were analyzed. The results show that during the thermal deformation process, the peak strain increases with the decreasing of deformation temperature or the increasing of strain rate, the dynamic recrystallization occurs, and the temperature has obvious influence on the microstructure of dynamic recrystallization. When the strain rate is 1 s-1, the recrystallization volume fraction and the grain size are the smallest. When deformed at low strain rate, the recrystallized structure is prone to mixed crystal. The relationships between critical stress and peak stress, and between critical strain and peak strain are determined by θ-σ curve, respectively.