Abstract: The static characteristics of a novel small float antenna base were studied. According to the geometric dimension and force status of the base, the float state, state equation and reserve buoyancy were studied. The buoyant centre, meta centre, meta centre radius and initial stability height were studied according to the weight transfer theorem, buoyant centre transfer theorem, the volumetric inclined theorem and the physical dimension. On the base of rotation invariance the static stability was studied by accuracy mathematical derivation. The relation between the dynamic righting arm and the static righting arm was got to study the large angle stability by analyzing the process of dynamic torque. The sink resistibility was studied by the reserve buoyancy. Results validate that the base has better buoyancy, stability and sink resistibility.