not illegal. Closed-loop management sealing is a prevention and control measure for epidemic situation. According to the provisions of the first paragraph of Article 51 of the Law of the People's Republic of China on Public Security Administration Punishment, those who refuse to implement the decisions and orders issued by the people's government in a state of emergency shall be given a warning or fined not more than 211 yuan; If the circumstances are serious, they shall be detained for more than five days and less than ten days, and may also be fined up to five hundred yuan. Refusing to implement the prevention and control measures put forward by the people's governments at or above the county level and the disease prevention and control institutions in accordance with the law on the prevention and control of infectious diseases, causing the spread of the virus or serious danger of spread, shall be punished according to Article 331 of the Criminal Law for the crime of obstructing the prevention and control of infectious diseases, and shall be sentenced to fixed-term imprisonment of not more than three years or criminal detention; If the consequences are especially serious, they shall be sentenced to fixed-term imprisonment of not less than three years but not more than seven years.