With the widespread application of 4K ultra-high-definition video technology in medical and security fields, field-programmable gate arrays (FPGAs) are increasingly employed for collaborative processing of large-scale UHD video tasks. To address the low data bandwidth utilization caused by 8b/10b encoding in high-speed transceivers, this paper proposes an FPGA-based 4K video board-to-board transmission and display system. The system architecture utilizes FPGA as the core controller, integrated with an STM32 microcontroller and GSV2011 codec chip to manage data transmission modes, while optimizing the hardware interface of GTX transceivers. By employing 64b/66b encoding in multi-channel GTX transceivers and designing encoding/decoding logic aligned with 4K video stream timing, the system achieves efficient transmission. Key innovations include multi-channel data synchronization mechanisms and DDR multi-frame buffering logic, effectively resolving channel-skew-induced transmission deviations and display frame tearing caused by clock rate mismatches during read/write operations. Experimental results demonstrate that the system stably realizes real-time 4K@60 Hz video transmission between boards with low hardware resource consumption. Compared with 8b/10b encoding, it reduces effective bandwidth requirements by 3.12 Gb/s while maintaining equivalent transmission performance. This solution provides a flexible, cost-efficient transmission framework for multi-FPGA collaborative processing in UHD video scenarios, demonstrating significant engineering application value.