The generating mechanism of circulating currents in parallel three-phase Boost rectifiers is analyzed.A model of the circulating current in αβ0 stationary coordinate system is established.Base on this，the circulating current is classified into three components:common-mode circulating current，differential-mode circulating current and high frequency circulating current.The affecting factors of three components are also revealed.With these understanding，controllers based on proportional and resonant regulators are designed separately for common-mode and differential-mode circulating current.Since rotating transformation and phase detection are eliminated in αβ0 coordinate system，a simple structure and small computational cost are achieved.Experiments are carried out on a 600 kVA mutual-driving test-bed.The results prove the validity of the analysis and the proposed control strategy.