Abstract: People's livelihood security is an important issue in China today. Though the government has paid more attention to the issue of people's livelihood security and the duty to afford, the fulfillment of the duty to protect is slightly less committed. Considering the important role the duty to protect plays in people's livelihood security, the fulfillment should be strengthened in the process. Due to the restrictions of the reason of state, the duty to protect should be restricted by a certain limit in the process. And based on this, following the internal structure of the duty to protect, achieving the aim by prevention, exclusion and relief is the proper strategy in the process of committing the state protection obligations of people's livelihood security.