In this study, a generating process of microscale local countercurrent flows between parallel electrodes with an applied electric field was investigated using a numerical simulation model for the computational analysis and experimental measurements. An insulating fluid containing dispersed dielectric particles exhibits rotational flow pattern generated with local countercurrent flows under an alternating electric field. These flow structures are formed under high-electric-field intensity and low-frequency conditions, and are generated after the electric field inversion. This phenomenon has enormous advantages for manufacturing processes and biomedical applications. A numerical model of this phenomenon is important to investigate the generating mechanism and to develop mechanical and biomedical applications. In this study, the Eulerian-Lagrangian method, which is both an analysis of forced particle dynamics in an electric field and a computational fluid dynamics (CFD) analysis, was used as a numerical simulation model. In this model, the forces acting on the polarized particles and local dielectric forces were calculated based on the local nonuniform electric field. Furthermore, the surface property of an individual particle was designed as the microscale diamond particle of surface termination. As a result, the calculated flow structures agree with the experimental results of the generating process of the rotational flow. It is clear that this numerical simulation model is able to calculate the generating process of the rotational flow under an alternating electric field.