The incubation period of SARS is generally about 1-16 days, most commonly 3-5 days, and SARS is an acute respiratory infectious disease caused by SARS virus infection, also known as infectious atypical pneumonia, which has a rapid onset, strong contagiousness and high mortality rate. After the incubation period, patients often have fever as the first symptom, cough and a small amount of sputum in the early stage, and respiratory symptoms such as shortness of breath and difficulty in breathing can appear as the disease progresses. This virus is also spread through respiratory droplets and close contact, so it is important to do a good job of protection and prevention to reduce the possibility of virus infection.