A straightforward and efficient split-model optimization technique, utilizing both analytical and simulation methods termed as Hybrid method, was developed to optimize the coupling system of a helix traveling-wave tube (TWT). This innovative approach addresses the complex challenge of designing RF power coupling into a non-uniform helix pitch segment supported by attenuator-coated support rods within the output section of the slow-wave structure of the TWT. This design task becomes especially intricate when employing an H-plane-end launcher transition rather than more conventional E-plane transitions, such as probe or door-knob types, which are typically used to minimize the coupling system’s size while improving S-parameters. By employing this split-model optimization technique, the simulation or computation time was reduced by over 95% compared to conventional optimization methods, all while maintaining the desired response in the voltage standing wave ratio (VSWR) within 1:1.4. The optimized VSWR obtained using the proposed split-model technique and the conventional simulation technique are agreed within 6–10% between them.