A new structure of space integrated information network is proposed in this paper, in which the LEOs are users to the backbone network, rather than parts of it. The structure is named as LEO-user-oriented space network. This paper first introduces traditional concept of space information network, then discusses the new concept of the LEO-user-oriented architecture, next probes into some key techniques related to the space information system, including laser links, routing and access technology. At last, feasibility of the walker constellation is proved though simulations.