In the early stage of the spread of corona virus disease 2019(COVID?19）epidemic， there are some problems in the early warning system constructed with the Law of the People’s Republic of China on prevention and control of infectious diseases as the core. This paper briefly expounds the provisions of the early warning system in the Law of the People’s Republic of China on prevention and control of infectious diseases， which compares and analyzes the international lying disease early warning system， pointing out the existing problems of Chinese infectious disease early warning system and putting forward the relevant suggestions from the perspectives of early warning authority， early warning situation， “whistle?blower” protection clause and accountability system， which provides reference for the improvement of the early warning system of infectious diseases in China.