The principle of trust protection is embodied in the article 8 and article 69 of the "Administrative License Law" in China's administrative law. Established in the Administrative License Law since 2000, the principle has been constantly improved and widely applied in judicial practice, and has a remarkable effect on restricting public power. However, as a principle gradually emerging in the field of administrative law in our country in the early 20th century, it needs to be improved in both theoretical level and judicial application. This paper USES case study method to study and discuss the conflict between theory and practice in the application framework of the principle of trust protection in judicial practice and the lack of procedural protection in its application.