With the increasing demand for the output beam intensity and pulse time of the neutral beam injector in the magnetic confinement fusion experimental device, it is urgent to carry out research on high-power large-area RF ion sources. It is the key to designing an impedance matching network that can deliver the maximum power of the RF power source to the coil and couple it to the plasma, thus to achieve large-area, high-density and uniform plasma discharge. Based on the previous research on single driver RF ion sources, the impedance matching network of dual driver RF ion sources was optimized and analyzed. The key parameters of the matching network were calculated, and the topology of the matching circuit was optimized. In the experiment, frequency tuning was used to tune the matching network. Stable and repeatable plasma discharge with 140 kW high power and 1000 s long pulse at 25 kW was achieved under dual drive. Subsequently, based on stable plasma discharge, the issue of power distribution uniformity between the two drivers was studied. The experimental results indicate that the optimized design of the matching network is reasonable and feasible, and the RF power distribution of the upper and lower drivers is basically uniform, laying the foundation for the upcoming negative ion beam extraction in the CRAFT (Comprehensive Research fAcility for Fusion Technology) NNBI (neutral beam injection system) project.