Cross-border travel often presents challenges in document storage, which can burden travelers. This study addresses the issue by designing a credential bag that enhances safety, convenience, and environmental sustainability. Utilizing design research, we applied the KANO model to categorize user needs, employed analytic hierarchy process to prioritize these needs, and used quality functional deployment to translate them into specific design elements. The KANO model has identified a total of 18 demand indicators, including “must-be”, one-dimensional, and attractive. An analytic hierarchy process analysis of the secondary indicators found that demands for the security of anti-theft, partition storage of documents, a variety of carrying methods and green sustainability have relatively high weight. The innovative solutions derived from the KANO-AHP-QFD model improve design practices and user experience in document storage. This approach offers a scientific and practical reference for the sustainable development of travel supplies and the luggage industry.