The micro structural evolution and the mechanism of recrystallization grain growth (GG) were studied during re-aging process in the Cu–Ni–Si alloy containing finely pre-aging δ-Ni 2 Si precipitates using computer simulations based on a diffuse-interface phase-field kinetic model, in which the temporal evolution of the spatially dependent field variables is determined by numerically solving the time-dependent Ginzburg–Landau (TDGL) equations for the structural variables. The results show that the finely dispersed pre-aging δ-Ni 2 Si particles exert a strong pinning effect on the recrystallization grain boundaries (GB). Initially the GG accords with the power growth law with n between 0.3 and 0.4, followed by a gradual transition to growth stagnation. The final grain size follows a Zener type relation <R>=1.41⁎(r/f a 0.49 ), with r the radius and f a the area fraction of the particles. The simulation results are compared with theoretical relations and previous simulation results.