Since the outbreak of COVID-19 epidemic, the global economy has continued to be turbulent. The large-scale market panics have led to an accelerated accumulation of financial risk in a short period of time, which triggered violent fluctuations in the international stock market. Hence, market sentiment monitoring is vital to maintaining financial stability. In this context, this paper effectively measures China""s systemic risk by combining text sentiment with topic concentration. Specifically, we construct a sentiment index, and use the cosine similarity of the text vector to measure the topic concentration, according to multiple authoritative news reports and “China Financial Stability Report”. The results show that the sentiment index is closely related to financial risk and macroeconomic fluctuations. During the international financial crisis, the European sovereign debt crisis, the Sino-US trade war, and the outbreak of the COVID-19 epidemic, the sentiment index has declined sharply. We further discuss the prediction ability of sentiment index and topic concentration by using correlation analysis, nonlinear Granger causality test, regression analysis and impulse response. We find a positive relationship between market sentiment and systemic risk. And the improvement of topic concentration means the accumulation of potential risk. In addition, compared with traditional risk indicators, the systemic financial risk index based on textual analysis contains more incremental information, which can significantly improve the out-of-sample forecasting ability for financial risks. Finally, according to the word cloud analysis of “China Financial Stability Report”, we identify the key financial risk areas in recent years. On the basis of above findings, we put forward several suggestions on how to guide investment sentiment, and how to build a public opinion monitoring and risk prevention mechanism based on textual analysis, so as to create a more stable financial environment during the 14th Five-Year Plan period.