The invention relates to an AC-DC hybrid microgrid active power flow control method and device. The method comprises the steps acquiring AC frequency fka for each alternating current subnet which is connected to a direct current system through an interface converter; determining DC voltage reference value Vdk.ref of the corresponding interface converter according to the AC frequency fka, wherein the size of the DC voltage reference value Vdk.ref is further related with a frequency range allowed by the alternating current subnet corresponding to the interface converter and a voltage range allowed by the direct current system; and performing PWM control on the interface converter according to the DC voltage reference value Vdk.ref by being combined with a reactive power instruction. The method and device provided by the invention realize that each sub-grid load is sufficiently and uniformly distributed according to the subnet capacity and the active margin, and the utilization ratio of energy is improved.