To avoid the collision between end-probe and space robot carrier or the spacecraft to be tested, 3D simulations are required for trajectory planning method of end-probe before the actual on-orbit measurement. In view of the nonvisual problem of the existing simulation system of space robot, a 3D simulation system based on virtual reality technology is designed. First, 3D solid model of space robot is established based on Open Inventor, and the 3D scene of space robot logical location is set up. Then, the visual 3D simulation system of space robot is created based on the data transmission technology and 3D scene. Finally, the kinematics model of space robot is established and the circular trajectory of the space robot end-effecter is planned. Simulation results indicate that the motion process of space robot and the motion characteristics of the space robot base can be obtained visually. This system facilitates the simulation study on the method of space robot trajectory planning and control, and avoids the collision of space robot due to improper trajectory planning.