Plain orifice impinging injectors are widely used atomization devices characterized by a simple structure and low manufacturing cost. Their atomization process is achieved through the impingement of two jets. In this study, a coupled VOF-to-DPM multiphase flow model, combining the volume of fluid method with the Eulerian-Lagrangian approach, was employed to numerically simulate the atomization process of two impinging jets. The reliability of the numerical simulation was validated by comparing the calculated breakup lengths of the post-impingement liquid sheet with experimental data and numerical results from the literature. The results indicate that a fan-shaped liquid sheet forms after the impingement of the two jets. The velocity on both sides along the impingement line is approximately equal to the jet velocity and exhibits an axisymmetric distribution, while the velocity component in the Z-axis direction shows an approximately centrosymmetric distribution. Furthermore, a smaller jet orifice diameter results in a thinner liquid sheet and greater instability, thereby promoting primary breakup and secondary atomization, which leads to enhanced atomization performance.