Abstract: Hot deformation behavior of BH10Mn2G welding steel was studied by using Gleeble-1500 thermal mechanical simulator in the temperature range of 900-1 050 ℃ and at strain rates of 0.10-10 s-1.Deformation activation energy Q=301.11 kJ/mol and hot deformation equation Z=3.281×1010exp(0.039 73σm) are worked out and diagrams of dynamic recrystallization state are drawn by compession analysis.These provide basic data for the prediction and control of the microstructure and properties of BH10Mn2G welding steel.