In this thesis, an interpolator based on the NURBS curves algorithm for a six-axis robot manipulator is proposed and the MATLAB is applied to simulate the motion trajectories of the end effector of a six-axis robot manipulator. In the comparison of the simulation results of the linear curve, smooth curve, cross curve, and oval curve, we can see that the proposed NURBS Interpolator can let the trajectory planning of the trapezoidal velocity curve, the angle and acceleration of the each motor, and RPM change have continuous results. Therefore, the proposed method in this thesis can really let the end effector of a six-axis robot manipulator move smooth and stable.