Fine grained bainite–aided DP steel was produced by CGP and intercritical annealing with the achieved grain size of 470 nm. Fine morphologies, high dislocation densities and carbon content of bainite resulted in the largest BH value. Flow curves of DP steels before and after BH can be fairly described by micromechanics based model and RVE simulation. DP microstructure with bainite showed more homogeneous stress and strain distributions and large energy absorption value.