Public health is a public service that concerns the public health of people in a country or region. In today’s world，the international public health security situation is becoming increasingly complex and severe under the influence of multiple factors. Public health is not only a domestic affair，but also a huge challenge that countries must face together. Public health security is a common challenge facing mankind and requires all countries to work together to address it. In recent years，global public health governance has become an important topic of the G20. Countries increasingly attach importance to the building of public health security capacity and gradually play a role in ensuring global public health security. The results show that no country is ready to deal with the global health security crisis；G20 countries generally perform well in “monitoring” and “risk” indicators，while “response” indicators are generally weak；European and American countries have strong public health security capabilities，but there are still shortcomings；The public health security capacity of developing countries contains considerable potential. Based on this，countries should strengthen the construction of their own public health security capacity and do a good job in crisis response；G20 countries should accelerate public health security cooperation between countries and international organizations as well as between countries，and all member countries should also actively cooperate；As an emerging developing country，China should play its own advantages and role in dealing with public health crisis；GHSI indicators are not universal and need to be improved.