In this paper, the parameters of power quality indicators analyzed theoretically time domain simulation, frequency-domain simulation, and the Fourier transform, multi-scale morphological wavelet transform and spectral analysis of power quality characteristics. Through these analysis methods this paper focuses on three-phase power quality characteristics unbalance and harmonic methods of software testing. This paper made ??an experimental prototype of CNC system is running its power input power quality testing, the test shows that this method can be used in analyzing real-time detection of power quality indicators, so as to the parameters of power quality indicators provide a reliable data.