This small courtyard building of 2000㎡ solves the basic function of security of the building, and is beneficial to the installation and use of CCTV. The space layout is compact and flexible, which facilitates open diplomatic reception and private life of staff. The planning meets the local requirements, merged into the urban context, creates a series of space, and solves the topological relationship between the open platform and private life in the same courtyard. The overall shape and architectural details convey the traditional chinese style and long cultural tradition. The concept of sustainable development supports the application of appropriate construction technologies. The setting of climate buffer zone not only prevents direct sunlight, but also solves the problem of outdoor use of AC. At the same time, it strengthens the sense of sequence and ritual of facade.