The main purpose of filling out the health declaration form before the start of school is that the school wants to know whether the students are healthy or not. If you are not healthy, you should truthfully report where you have been during the holiday, who you have contacted, and the transportation and accommodation when you go.
According to the State Council's Emergency Regulations on Public Health Emergencies, different subjects will bear different legal consequences if they conceal, delay reporting or lie about the epidemic situation.