[Purpose/significance] Short videos have gradually become one of the primary channels for the public to ob⁃tain information. Through short videos, various types of information can rapidly disseminate among users, including a large number of false short videos. Many of false short videos are adopted or shared by users, it may harm them and dis⁃turb the online information environment. Therefore, this study explores the factors influencing the dissemination of false short videos, in order to provide references for the governance of false short video and the optimization of online in⁃formation ecology. [Method/process] To explore the influence of content sentiment of false short video on user emotion and false short video dissemination effect, this study employed user sentiment as a mediator and content relevance as a moderator, constructed the research model based on the CAC Model and ELM Model, and then collected 1007 effective false short videos from the TikTok, extracted image, text and audio sentiment from these false short videos based on text
sentiment analysis, image recognition, and other technologies. As such, the study verified the moderating effect of con⁃tent relevance. [Result/conclusion] Images, text and audio sentiment of false short videos exert significant positive ef⁃fects on users' emotions in different degrees, while the author's avatar and background music exert no significant effect on users' emotions. User emotion exerts a significant negative effect on dissemination effect of false short videos, and partly plays a mediating role between the content sentiment of false short video and its dissemination effect. Content rel⁃evance significantly moderates the influence of the negative impact of user emotion on false short video dissemination effect.