Stewart platforms have recently attracted attention as simulator and machine tools because of their conceptual potentials in high motion dynamics and accuracy combined with high structural rigidity due to their closed kinematic loop. Dynamics design of Stewart platform based on Newton-Euler is presented in this paper firstly. Its aim is to compute the velocity and acceleration according to the index given. Meanwhile, the matching rule is put forward in the design of hydraulic power unit, which requires the power capacity of driving units surround the edge of payload. Based on these principles, optimal driving can be obtained practically. This paper, composed of driving units design and optimization, attempts to ground the foundation on dynamics design and choice in the future.