Hydrogen energy, as a highly promising clean energy source, faces a critical bottleneck in achieving industrial implementation due to the challenges of large-scale, long-distance storage and transportation. Given the high costs of hydrogen transportation, injecting hydrogen into natural gas pipelines for blended storage and transport has emerged as the core technical pathway for large-scale hydrogen energy transportation, playing a significant role in advancing the development of the clean energy industry. A systematic review and summary of existing research on hydrogen blending with natural gas was conducted. First, the blending mechanism of hydrogen injection into natural gas was elucidated, research methods employed by scholars both domestically and internationally in the field of hydrogen blending with natural gas mixers were summarized, and the structural types of mainstream mixers were analyzed, such as T-junction pipes and static mixers, examining the impact patterns of different blending structures on mixing uniformity. Next, the application scenarios and practical value of artificial intelligence in the hydrogen injection process were further explored, highlighting its technical advantages in improving blending efficiency and ensuring system safety. Finally, a comprehensive summary of the current research status on hydrogen injection into natural gas was provided, and future key research directions for this technology were proposed from the perspectives of gas distribution and pipeline design, blending technology and equipment optimization, precise control and operational optimization, as well as system complexity and intelligent management. The aim is to promote the iterative advancement of hydrogen injection technology into natural gas pipelines, offering theoretical support and practical references for building a zero-carbon hydrogen pipeline network.