The ozone injection process for NO control was studied using an ozone-NOx reaction coflow jet by direct numerical simulation. A 65-step detailed kinetic mechanism for the O-3-NOx reaction was developed and verified by our experiment and another published experiment. The detailed kinetic mechanism was incorporated into a 2D reaction jet flow and handled by Chemkin. The code was parallelized and run on a cluster system. The reactions between O-3 and NOx are relatively slow compared to the turbulence time scale. The chemical reactions occur mostly in the core of all kinds of vortexes. The dynamics of vortexes make a great contribution to the mixing of the reactants and reactions. The vortexes begin to roll up alternately at about 7d from the root of the jet. The order of the two-line vortexes become disordered after 10d. NO2 is the main product of the O-3-NO reactions, NO3 and N2O5 are the minority products. Favre averaged results show that about 45.44% of NO can be oxidized by O-3 at the 30d outlet of the computational domain.