Time grating displacement sensor is briefly introduced for measuring space with time. The measured values of time grating will not update during the measuring period. To use the sensor as position feedback component for CNC rotary table positioning servo control, this paper firstly introduces prediction conception to measurement field, and predictive measurement method is firstly proposed. Predicted values are derived form past measured values and the prediction error is corrected in real time using the new measured values. The positioning accuracy of the CNC rotary table is improved greatly. Experiment results conform the validity of the proposed method.