Faced with the COVID-19 pandemic, countries have implemented stringent preventative measures. Individuals impacted by quarantine policies have become more reliant on cell phones to interact with others. It is still uncertain whether recurrent internet talks of one's struggle aggravate anxiety and despair in individuals. This study investigated the effects of social media-based co-rumination on mental health. In this study, 352 Chinese participants were recruited online, took the online test, and returned 309 valid surveys. There were 127 men and 182 women among them. The researchers looked into the relationship between respondents' co-rumination, balanced time perspective, anxiety, and depression. The study discovered that persons under quarantine had higher levels of co-rumination, but this did not result in more acute anxiety or despair. The unbalanced time perspective negatively moderated the association between the two variables, but the balanced time perspective had no moderating impact. The cognitive style of co-rumination predicted psychological disorders negatively.