Wuhan lockdown has affected individual psychological status while effectively curbing the epidemic. It is difficult for traditional questionnaire method to acquire individual psychological assessments in large scale timely, which makes it hard to propose time-effective psychological services. In this study, we extracted the linguistic features of Weibo posts from January 20, 2020 to February 16, 2020 among 41 105 active users, and identified the changes of Wuhan citizens' psychological status nonintrusively. The results indicated that Wuhan citizens have been in a high state of negative emotions such as anxiety, anger, hostility, and disappointment in short term. Meanwhile, the lockdown had induced more fear, psychological pain, and stress experience to some extent. In addition, the lockdown reduced the usage of leisure words and increased the frequency of working words in Wuhan residents' language expressions. The results suggest that we should take targeted services according to the different negative emotions raised, and arrange long-term service for negative effects of stress, and incorporate online public psychological detection and service into national emergency management system.