One of the important reasons for the current lack of trust in food safety among the public is the information asymmetry existing in the relevant core stakeholders. The primary prerequisite for building public trust mechanism of food safety is to clarify the rights and obligations of the stakeholders of the judiciary, government, enterprises and the public based on the background of information asymmetry. Based on an overview of the basic theories of public food management, this study discussed the main dilemmas that the current public food safety trust mechanism is difficult to form, and points out the main scopes and basic principles of building public food safety trust mechanism. we suggested that through cultivating a social environment based on judicial construction, the government's administrative management system and methods should be improved, and the industry self-discipline construction of food companies should be strengthened. Finally, the public participation in food safety would be enhanced and a public food safety trust mechanism could be established.