This is a two-phase, non-randomized clinical trial conducted in eight communities in Miyun District, Beijing. The study first develops and validates a reliable 18-item questionnaire (Knowledge, Attitudes, and Practices \[KAP\] scale) to assess community residents' understanding, attitudes, and behaviors related to secondary hypertension. Then, we evaluate whether a 1-week community-centered short-video health education intervention (five 1-minute videos delivered via community WeChat groups by local physicians) can improve residents' secondary hypertension-related knowledge, attitudes, and practices. We will compare scores before and after the intervention, and analyze which groups (such as rural residents, people with lower education, older adults) benefit more. This study aims to provide a simple assessment tool and a scalable health education model for secondary hypertension in community settings, especially for rural and low-educated populations.