With the enlargement of the softwares cope and the increase of the complicated level, the success of software development is not depended on the selection of data organization and software algorithm completely, but to great extent is depending on the software systems structure, the software system structural models become the key which influences software. A proper architectural approach leads to shoter software development life-cycles, resulting in savings in software development and maintenance cost. After analyzing several common software architectural styles, a new software modeling approach- architecture model based on the middle layer is presented. Then, through a practical example-the campus card system. It supports the new architecture model-middle-layer software architecture