The accuracy of nucleation parameter is a critical factor in the simulation of microstructural evolution during dynamic recrystallization (DRX). Based on the flow stress curve under hot deformation conditions, a new approach is proposed to identify the nucleation parameter during DRX. In this approach, a cellular automaton (CA) model is applied to quantitatively simulate the microstructural evolution and flow stress during hot deformation; and adaptive response surface method (ARSM) is applied as optimization model to provide input parameters to CA model and evaluate the outputs of the latter. By taking an oxygen-free high-conductivity (OFHC) copper as an example, the good agreement between the simulation results and the experimental observations demonstrates the availability of the proposed method.