Public Health Law is not only the law regulating the exercise of national public health power，but also the right law to guarantee the citizen’s right to physical and mental health and personal safety，whose key purpose is to safeguard the public health. Public Health Law has a long history，showing a dual pattern of the rule of law for regular public health and the rule of law for emergency public health. China’s legal system of public health has formed and accumulated certain institutional resources in many aspects，such as norm creation，administrative law enforcement，judicial operation and law-abiding mechanism，but there are also some shortcomings and deficiencies. Improving China’s legal system of public health should start from the dual pattern of the rule of law for regular public health and the rule of law for emergency public health，coordinate the construction of the normative system by planning and compiling the public health code，implement the law enforcement mechanism of “integrating health into all policies”，strengthen the judicial security system with the core of the judgment function，and build the public health law-abiding system with the core of the health promotion mechanism，so as to finally realize the modernization and legalization of the public health governance.