Abstract: Controlling principle of CNC test-bench was discussed based on motion controller.Institutional design scheme was introduced.Entire test-bench adopting modularity design had simple structure，so that it was practical and easy to maintain.Against the friction problem within precision CNC test-bench，model and simulation of the servo system was implemented by MatlabSimulink.By comparing the simulation results with the known experimental data，the feasibility design of test-bench was verified.It provides the basis for subsequent improvement.