A novel system is proposed to simulate the spatial microgravity environment for big and middle experimental objects with complex move.The equipments combine machine transmission、motor drive and air-bearing to realize three-dimension spatial microgravity simulation.Friction non-linearity of machine system and outside disturbance are considered.Sliding model controller based on neural network is employed to reduce disturbance and uncertainty.The experimental result shows that the test equipment is light weight,convenience and precision,it compensates non-linearity infection for grasping of robotic manipulator,and it has important engineering value to three-dimension spatial microgravity simulation.