Abstract: The storage devices, including registers, caches, main memory, and exterior devices, are organized as a hierarchical system. In the traditional operating system, there are two data memory models, one is the process virtual address space that is constructed at the level of main memory, and the other is the file that is constructed at the level of exterior storage device. It is supposed to be unnecessary to construct the process virtual address space; there should exist only one data memory model——the file, which is constructed on the exterior device level; the main memory should be used as the file buffer; instructions access the file directly and the processes are run on files. Based on these ideas, an operating system model is proposed, its structure and one of its prototypes are discussed, and its performance is tested and evaluated. Finally, its advantages as well as disadvantages are analyzed.