Make a detailed analysis of the decoupling rectification strategy based on instantaneous reactive power theory and non decoupling control strategy based on traditional double closed loop. Comparative analysis are made from complex of control, rectifier DC voltage steady-state and transient stability etc.. Non decoupling strategy have advantages of simple structure, but the inner current loop based on traditional PI control can not eliminate the alternating current static error; Decoupling control can eliminate the both inner and outer loop static error and voltage steady-state performance is good,but control is complex. Both strategy can make the power factor be 1. The experimental results prove the correctness of the analysis.