Aiming at the evaluation and calibration of the total distortion of the partial period sinusoidal signal waveform, a technical solution is proposed, which includes directly using the partial period sinusoidal curve fitting method for parameter estimation and residual estimation, then correcting the distortion according to the measurement system range and effective bit, and finally giving the evaluation result of the total distortion of the partial period sinusoidal waveform. At the same time, the measurement and evaluation of harmonic distortion in the partial period waves are discussed, and the conclusion that the harmonic analysis error of the partial period waveform is large and the evaluation result of the harmonic distortion is much larger than the total distortion is obtained. The harmonic analysis of partial period sinusoidal waveform is not yet practical. Based on a set of ultra-low frequency vibration experimental data, the evaluation results of the total distortion of the partial-period and multi-period sinusoidal waveforms are compared, which verifies the effectiveness and feasibility of the method in this paper.