COVID-19 is part of a global pandemic.  Which greatly affects the lives of people in society And this COVID-19 outbreak has forced many schools to switch to online teaching methods.  These changes have also affected the stress of high school students.  The purpose of this study was to study the factors affecting the stress of students when they switched back to onsite learning.  After the outbreak of COVID-19 And we collected 241 responses from high school students to a survey to assess the stress of high school students after returning to onsite classes.  And found that 49.91% of students were very stressed.  And there are 29.91% of students with low stress.  From the survey results, it was found that most students were stressed that they had to change their teaching from online to onsite.  Which is affected by the COVID-19 epidemic And these may lead to health problems in the future.