A pin-limited digital microfluidic system was designed and implemented in order to address the limitation of system throughput imposed by the number of control pins in the digital microfluidic system. A modular design was adopted to decouple the control circuitry from the electrode array, enabling configurable expansion of the number of parallel channels. The similarities and differences between single-droplet actuation and parallel multi-droplet actuation were analyzed based on the fundamental principle of electrowetting on dielectric. The effect of reservoir structure on droplet generation performance was evaluated on the developed platform, and the influence of the number of parallel droplets on droplet actuation performance was analyzed. The experimental results demonstrated that the TC reservoir effectively reduced the minimum driving voltage required for droplet generation, with a maximum reduction of 14.70%, while the coefficient of variation of droplet volume decreased from 1.32% to 0.57%. Variations in the minimum driving voltage required for droplet transport and splitting, compared with the single-droplet case, remained within 1.5%, and the coefficient of variation of droplet volume after splitting consistently remained below 3% under conditions of up to seven parallel droplet groups.