A flexible pneumatic spherical joint is mainly composed of three columnar elastic shells which are reinforced and restricted by embedded spiral metal wire. It is driven directly by compressed air. Following a brief introduction of the structure and working principles of the flexible pneumatic spherical joint, the static model is constructed to describe its properties. From this model, it can be seen that the bending angles can be obtained by controlling pressures of air inside the joint. Analysis, simulation and experiments are carried out for this joint. The static model is proved to be feasible by the comparison between experimental and simulating results. The spherical joint has advantages such as low price, simple structure and perfect flexibility. It can be applied to multi-fingered hand design.