Purge operation in fuel cell vehicles constitutes a critical post‑operation process for fuel cell engines, and its efficiency directly determines the engine's cold‑start capability and overall system service life. To elucidate the underlying mechanisms, functional definitions, and engineering implementation approaches of the purge process, this paper employs a combined method of bibliometric analysis and patent analysis to systematically investigate purge technologies for fuel cell vehicles. The results indicate that such technologies are characterized by the following features: (1) Purge architectures and strategies must be tailored to different operating conditions; (2) For a given operating scenario, optimal trade-offs between technical performance and economic cost should be pursued; (3) The optimal engineering realization of purging under specific conditions is not merely a water removal procedure, but rather a systematic decision-making process that integrates considerations of purge medium, target objects, operational parameters, and termination criteria, while simultaneously accounting for multiple constraints such as vehicle energy efficiency, performance recovery, service life, and safety.