Abstract: To balance gravity, a balance set with high respond speed and precision was designed. The set adaptable to high and low temperature was installed in the inside of the docking mechanism. Relative techniques are introduced, such as spherical gemel hoisting mechanism that made the active docking ring rotating in three-dimensional direction, intelligent gravity balance technique that could provide the force with high speed and precision to balance gravity and could automatically follow with the active docking ring, two-dimensional translation wheel technique that ensured balancer following the active docking ring. The friction and inertia resistance were very small by the design of lessening weight. An experiment about the wheel design was done. The results show that the equivalent weight friction coefficient is only 0.004 17. So the respond time of the whole design should be less that 10 ms. The error of simulated weightlessness is about 1%~2% in each direction.