Abstract: Purpose/Significance The tendency of social network content to be homogeneous has been partially confirmed by some studies, but the analysis is inadequate about whether and how the closure of content is conducted. Based on the sample of Weibo platform, this study explores the issue about how to trigger and set the overall closure of content. Design/Methodology Through Granger Causality Test, the results show that in social network, the closure of top content can cause and trigger the closure of overall content, but not vice versa. The mechanism may be related to the popularity of content: the higher the popularity of content, the stronger its ability to cause changes in the proportion of various types of content, and thus the greater the possibility to trigger the overall closure. Conclusions/Findings The findings reveal the phenomenon that overall content may tend to be closed under the control of external force, which is a deeper insight into the problem of content closure in social network. At a practical level, this paper has reference value for avoiding and regulating the closed social network caused by some popular content.