By focusing on the draft for public comments of the new subject catalogue of the art, the article points out that design as an interdisciplinary discipline has divided the original design into three parts, belonging to three disciplines: theory, practice and interdisciplinary, which separates the intersection of original design theory, design practice and technology, and obscures the truth of design research. The article discusses that the theory, practice and technical factors were forcedly separated by the new interdisciplinary design, and overemphasizes the influence and cross-integration of the technological frontier in industrial design on design technology, which is not conducive to the overall cognition of design research, and also dismembers the subject characteristics of the design science. The article expounds that the new subject catalogue is a disregard for the research of a wide range of design categories, which will inevitably lead to the pan-technicalization of design research, which will promote the excessive interpretation of the outer edge of design, and make design lose the truth of the design profession. Furthermore, the article proposes a path thinking on how to return to the truth of design by the discipline attributes of design.