A “two steps measures” for series power quality regulator(SPQR) in its limitation voltage is proposed based on the analysis of the pre-sag voltage compensation strategy’s optimal compensation aim. The proposed measures can make the equipment realize the optimal compensation aim with its fullest ability. The analysis formula and influence curves of optimal compensation aim show that the equipment’s optimal aim is influenced by three factors which include the limitation value of the compensation voltage, magnitude and phase of the source voltage. In addition, the source voltage variation scope which can realize the optimal compensation aim in limitation voltage is given. The analysis results will be useful to compensation strategy design and engineering practice.