Following the driving mode problem for the spherical motion mechanism, a new type of hydraulic drive spherical joint with two degrees of freedom was proposed. The full cycle rotating motor and a rudder blade swing motor were used as drive in the joint mechanism, and a spherical surface output in all directions could be achieved. The dynamics and trajectory tracking control of the spherical mechanism was researched. Firstly, considering the effects of the inertial force and gravity, the Lagrange equation and Euler equation were adopted and the dynamic model of the spherical joint was established. On this basis, a decentralized robust adaptive control strategy was utilized for the joint trajectory tracking. The controller was made up of a linear PD feedback and a nonlinear adaptivefeedback of compensating uncertainty dynamics, the effects such as frictions and external disturbance could be overcome effectively, and the only information required in setting up the strategy was the output position and speed states of the joint. Finally the global asymptotic stability could be warranted. It is shown by the simulations that the spherical joint has a good capability of trajectory tracking to use the control strategy.