As the digitalization of cultural heritage protection accelerates, virtual reality (VR) technology, with its immersive and interactive nature, is increasingly becoming an important medium for showcasing and disseminating cultural content. However, existing VR cultural heritage experiences often suffer from issues such as limited interactivity, fragmented information presentation, and a lack of user guidance, which hinder their educational value and engagement. This study adopts a User-Centered Design (UCD) approach as its core methodology, aiming to explore how to optimize the user experience of VR cultural heritage. The research first reviews literature and analyzes case studies to identify the application strategies and shortcomings of UCD in VR cultural heritage projects. It then takes the Dunhuang Mogao Grottoes Cave 003 as its subject for prototype design and development. Prior to prototype construction, user needs and pain points were collected through questionnaires and semi-structured interviews. Based on this data, the first version of the prototype was completed, followed by small-scale user testing using observation, interviews, and a User Experience Questionnaire (UEQ) for evaluation. Based on feedback, iterative optimizations were made in the second version of the prototype, significantly enhancing immersion, engagement, and the educational value of the VR cultural heritage experience. The research results validated the applicability and effectiveness of the UCD method in VR cultural heritage design and provided an actionable reference path for future digital cultural heritage project experience optimization.