Abstract: In the domestic spacecraft development, the structure contours and the mechanical interfaces of various subsystems are the main challenges in the three dimensional layout designs of spacecraft. Various brackets to install various kinds of equipment in the spacecraft have to be designed. Consequently, the spacecraft would become heavier. Besides, the layout design of cables and pipeline is affected. Based on the analysis of the Soyuz spacecraft, a method of the contour matching design is put forward in this paper in order to reduce the number of fixing brackets.