On December 7 ^th of 2022, the province and the country experienced a huge adjustment of the prevention and control measures against SARS-CoV-2, which was called the ten actions. But we still performed regular SARS-CoV-2 nucleic acid testing for hospitalized patients before their admission, which could to some extent reflect the infection rates of the total society. A total of 2212 cases and 439 positive cases were enrolled in the study. The infection rate increases from the first to the third week, and then decreases from the third to the eighth period. The infection rate of the eighth week returned nearly to the rate of the first week. The adjustment on the prevention and control measures resulted in rapid increase of SARS-CoV-2 infection rate among hospitalized children through the first three weeks, and it took nearly eight weeks for the infection to recover to the rate at the beginning of the adjustment. Continuous monitoring of the infection is required in the future to help reduce the infection.