With the accelerating process of urbanization in China, renters in big cities have to choose to live in narrow small space houses under the pressure of rent. In the survey, it was found that the residents of these cities have the problem of crowded living conditions, and such urban population gathering also caused a huge burden on the ecological environment of the city. Therefore, this project puts forward the concept of "Compact living" and develops the concept of "Co-Living" second landlord business model, which can not only meet the living needs of urban renters, but also contribute to the sustainable lifestyle of reducing urban land use, energy consumption and domestic waste emission. And in this project, three interior design schemes that conform to the living conditions of Chinese cities are designed to better visualize the whole design concept.