— In the conventional five-year undergraduate architectural design teaching system, the second-year design teaching can be regarded as an introductory course for formally entering the training of architectural design methods, and the curriculum design goals at this stage are reflected in two levels, to guide students to understand the basic design logic and to master the rational design methods. Base on analyzing the problems of teaching methods that affect the training effect, such as the lack of "teachability" and "orientation" in conventional introductory courses, the second-grade teaching team of the School of Architecture in South China University of Technology has proposes a "decomposition" introductory teaching concept for the above problems, and summarizes two aspects of the design training innovation model as the "thematic" teaching content decomposition and "advanced" guidance process decomposition. Taking the first topic of the second-year design course as an example, it analyzes in detail of the specific operation method of the "decomposition" teaching mode.