This paper studies the variation trends of currents on the ground plate electrodes during positive streamer discharges in uniform and non-uniform electric fields, providing valuable insights for high-voltage insulation design and discharge physics research. A two-dimensional axisymmetric fluid model is established to numerically simulate the development of positive streamer discharges in both uniform (plate-plate electrode) and non-uniform (point-plate electrode) fields. By coupling Poisson’s equation, charged particle transport equations, and photoionization source terms, the propagation process of streamers is simulated. The spatiotemporal evolution of the total ground current and its components (conduction current and displacement current) is analyzed as the streamer approaches and reaches the ground electrode. The results show that in both electrodes, as the streamer approaches the ground electrodes, the displacement current in the outer region of the plate shifts from positive to negative, while it remains positive inside the streamer channel. After the streamer reaches the ground electrodes, the displacement current within the channel transitions from positive to negative, and the conduction current increases significantly. This study provides numerical evidence for understanding the mechanisms underlying various current variations on ground electrodes in uniform and non-uniform electric fields.