Abstract: Evaluating social security emergency policies, identifying policy deviations and institutional deficiencies, and putting forward optimization strategies can improve the social security policy system and improve the effect of public crisis management. This paper used the content analysis of the policy text and the PMC index model to quantitatively evaluate the SARS and COVID-19 epidemic prevention and control policy text. Based on the core characteristics of public crisis and social security, the index system was designed, the quantitative evaluation of China’s social security emergency policy in public crisis governance was obtained, the advantages and disadvantages of the social security system in dealing with the public crisis were identified, and policy suggestions to optimize the social security emergency response system were put forward. It is found that the current social security emergency policy system in China is superior and can effectively guarantee people’s livelihood and promote the restoration of economic and social order. However, in this policy system, the special social security emergency policy is few, the policy content predictability is insufficient, the policy tool combination effectiveness is low, the rights and responsibilities of policy subjects are vague and the policy evaluation mechanism is not perfect and so on. The social security emergency policy system should be optimized by strengthening the formulation of special policies, enhancing the predictability of the policy contents, improving the contents of emergency response mechanisms and perfecting the policy evaluation mechanism after the crisis.