The invention provides a compensation method and device for improving dynamic performance of a bus voltage between two-stage power converters, and belongs to the technical field of power electronics.When the output voltage udc of a single-phase PWM rectifier is used as a direct current input voltage of a phase-shifting full-bridge DC-DC converter on the backward stage, a negative bus is connectedwith an L1C1 branch circuit and an L2C2 branch circuit in the middle point of two bridge arms of the phase-shifting full-bridge inverter, wherein the L1C1 branch circuit is used for restraining 100Hzripple voltage of the direct current bus, and the L2C2 branch circuit is used for compensating the transient state drop of the direct current bus voltage due to load sudden change. According to the compensation method and device, the output voltage of the PWM rectifier with the low ripple voltage can be obtained under the condition that the capacity of the capacitor Cdc is obviously reduced, so that the power density of the whole system can be improved to a certain extent; and the dynamic performance of the output voltage of the PWM rectifier can be effectively improved, the transient state drop of the output voltage of the PWM rectifier is remarkably reduced, and the stability of the voltage of the direct-current bus is facilitated.