Since the beginning of the COVID-19 pandemic, Ministry of Education of the People’s Republic of China has not released the annual number of students studying abroad. This paper first proposes a monthly indicator, network public opinion factors for studying abroad, by the Principal Components Analysis (PCA) method using the daily search data of Baidu Index of study abroad keywords from 2011 to 2022. Then Mixed Data Sampling (MIDAS) regression is implemented for nowcasting the annual growth rate of the number of Chinese students studying abroad from 2020 to 2022. Finally, we evaluated the effects of COVID-19 pandemic on the annual number of students studying abroad by comparing the prediction results of the MIDAS model and the Grey model. According to the results of MIDAS model, the predicted number of Chinese students studying abroad in 2020, 2021 and 2022 are respectively 756600, 737171, 803022, and the annual growth rate are respectively 7.548%, - 2.568%, 8.933%. The sharp decline in 2021 means the COVID-19 pandemic has a serious adverse effect on international student mobility, and the rapid rebound in 2022 shares one sign of a possible rapid growth of the number of Chinese students studying abroad comeback.