Abstract:The problem of the experimental object design for ground experiment system of neutral buoyancy was one of the key to achieving demonstration effectually of the development of spacecraft. This paper studied the issues of the configuration design which based on the requirement of the experimental object. First, the relative position of the center of mass and buoyancy was design based on the Archimedean principle. Furthermore, the decision was made for the configuration of the experimental object. At last, the result of the design was verified reasonable by experiment.