With the development of human society and scientific technology, people's material production and social activities, cultural activities, and increasing the scale of scientific research, social contact is increasingly close, between departments of human's epistemological and methodological level is increasing day by day, gradually from the height of the overall and the system to recognize and solve the problem, to form the concept of system theory and related theoretical system. This article is around the software engineering of the defects in the system structure model conversion technology. On the basis of the focus on design pattern oriented model transformation method, the model of knitting and the metadata mapping were studied, based on the model driven architecture (MDA) is designed for Web application development platform, verify the validity of the above technologies and methods.