Abstract: Through studying the measurement of angular vibration parameter in the field of inertia and dynamic torque calibration.An angular vibration measurement and data analysis method using circular grating and windowed FFT is proposed.Firstly,collecting and storing the signal the circular grating sensor output by the high-speed data acquisition card,through the way of level accumulation obtaining the waveform contour.Then the synthetic waveform is sampled and which is calculated by windowed FFT.Finally,the angular acceleration parameters are obtained.An experiment is designed to test the measuring device with a standard angle shaking table,the experimental results show that the relative error between the angular acceleration measured by this method and the standard value is less than 2.5%，and the repeatability of angular acceleration is less than 0.3%，and the the uncertainty of the measurement results is evaluated.

Key words: Vibration and wave, Angular vibration, Angular acceleration, Circular grating, Windowed FFT