Transformative use, which originated in the United States, aims to balance the interests of copyright owners and dual creators and promote innovation. However, due to the controversy of its value orientation and the ambiguity of the applicable standards, it has not achieved the desired effect after being introduced into Chinese judicial practice. The academic community has focused on the specific policy level, lacking in‐depth discussion of its legitimacy, and the existing views base the value positioning of transformative use on the balance of interests or correcting market failures, which cannot effectively solve the problems faced and cannot exert its due benefits. Based on Rawls's theory of justice and Kant's theory of equality of rights, the interpretation of transformative use with the help of semiotic theory can provide a basis for legitimacy and provide specific judicial rules on this basis.