Abstract: Public sense of security is an important index to measure urban public security and evaluate the effect of government on urban public security governance.Based on the "frustration-aggression" theory and the differentiated trust mechanismmodel,this paper constructs a path of the impact of frustration experience on the public sense of security,and adopts the data of "2019 New Era Living Conditions Survey of Megacities" to conduct an empirical study.It is found that the public sense of security presents two dimensions of individual sense of security and social sense of security.The public frustration experience directly reduces the social sense of security,and both the individual sense of security and social sense of security are reduced by reducing government trust,policy identification and sense of social justice.Government trust,policy identification and social justice have differentiated effects on the influence path of public sense of security.Among them,there are "symmetry principle" of government trust and "asymmetry principle" of policy identification in the influence path of social security.The sense of social justice has become an important bridge for frustration experience to reduce individual sense of security and social sense of security.Therefore,it is of great practical significance to cultivate a risk communication mechanism,expand access to policy information,enhance the public's ability to perceive policies,and build a risk sharing and benefit distribution mechanism to ensure the public sense of security.

Key words: public, sense of security, frustration experience, government trust, policy identification, sense of social justice