With the outbreak of the COVID-19 pandemic, most colleges and universities have adopted VPN to ensure remote learning and scientific research when students and teachers cannot return to school. To understand the specific situation, we collect the VPN logs of Peking University during the COVID-19 pandemic from February 2020 to September 2020 and discuss the number of users, login and logout time, usage time, cluster analysis, and user categories. The maximum number of daily users of VPN is about 15 000, and the maximum number of concurrent users is about 5000. Moreover, the average daily usage time of VPN is up to 325 minutes. These data show that students and teachers rely highly on VPN for remote learning and scientific research. According to the daily average usage time and the number of days of use, the users can be roughly divided into 4 categories. The VPN usage time of science and engineering users is slightly longer than that of liberal arts users, but the trend of change is the same. These data are of reference value for understanding VPN usage and adjusting VPN resources. Although VPN has facilitated the acquisition of school resources during the COVID-19 pandemic, the security risks it brings cannot be ignored. If protections are not enough, the user terminal will be vulnerable to attacks by hackers, who can steal resources or attack other machines in school using the user terminal as a springboard. As remote learning and scientific research will become the new normal, is it “sweet” or “poisonous”? Colleges and universities should be well prepared to deal with it.