Addressing the issues of impurity particle precipitation and aggregation within existing converters, which can induce partial discharge or dielectric breakdown, this paper constructs a solid-liquid two-phase flow multiphysics model of fiber-metal mixed impurity particles blended with flowing insulating oil, based on the finite element simulation method. Through simulation studies under different flow rates and voltage amplitudes, the movement and aggregation characteristics of mixed impurity particles were investigated. Simulation results show that the oil flow significantly impacts the motion of fiber impurity particles, with an increase in oil flow rate leading to fewer collisions between particles and electrodes, thereby reducing the likelihood of mixed impurity particle aggregation into bridges. Moreover, as the voltage amplitude increases, the aggregation of fiber-metal mixed impurity particles between electrodes becomes more pronounced, and the impurity bridges formed are broader and more apparent. The electric field in the region between spherical electrodes exhibits an axially symmetric distribution, symmetrically distributed left-right and top-bottom, with the highest electric field strength in the area closest to the spherical electrodes and gradually decreasing in other areas.