Plastic deformation behavior of X12CrMoWVNbN10-1-1 ferrite heat-resistant steel was studied systematically at high temperature. The stress-strain curves were measured at the temperature of 950°C-1250°C and strain rate of 0.0005s−1-0.1s−1 by Gleeble thermo-mechanical simulator. The flow stress model and dynamic recrystallization model were established based on Laasraoui two-stage model. The activation energy was calculated and the parameters were determined accordingly based on the experimental results and Sellars creep equation. The verification was performed to prove the models and it indicated the calculated results were identical to the experimental data.