<p>Short-video platforms such as TikTok have become significant sources of health information, particularly among younger populations. However, the quality and reliability of health-related content on these platforms remain a concern. This investigation examines the current landscape of sleep disorder information on Douyin (TikTok in China). To evaluate the quality, trustworthiness, and thematic completeness of sleep disorder-related short videos on Douyin (TikTok in China). We conducted a cross-sectional study by retrieving the top 200 videos from Douyin using a combination of three Chinese keywords (“睡眠障碍” [sleep disorders], “失眠” [insomnia], and“睡眠” [sleep]). The top 200 videos from each keyword search were pooled. After removing duplicate listings, commercial advertisements, and off-topic videos, 154 videos were included in our final study. Engagement metrics—including likes, comments, favorites, and shares—were collected to quantify the influence of the short videos. The quality of these videos was evaluated using the modified DISCERN instrument, the JAMA benchmark criteria, the Global Quality Scale (GQS), and a content-specific tool designed to assess six key domains. Double-blinded assessments were performed. Most videos were created by healthcare professionals. Overall quality was moderate (median scores: GQS = 2, JAMA = 2, mDISCERN = 2). Notable content gaps were identified: 34.4% lacked information on detection, 40.3% provided minimal treatment details, and 52.6% omitted outcomes. Videos from healthcare professionals scored significantly higher (<i>p</i> &lt; 0.05). Engagement metrics correlated positively with quality scores. Sleep disorder-related content on Douyin (TikTok in China) is of moderate quality, with professional sources demonstrating superior reliability, suggesting the need for greater efforts to standardize health-related content on such platforms. Strengthening content verification and encouraging professional involvement are essential.</p>