The utility model relates to a mixed microgrid system of alternating current -direct current to solve the problem that how to reduce system's electric energy loss of causing because of current switchover. This system includes: ac bus is suitable for the connection alternating load, the dc bus is suitable for and connects the DC load, a power supply system, with ac bus connects, the 2nd power supply system, with the dc bus is connected. The utility model discloses in not only include and also include the dc bus by ac bus, a power supply system accessible ac bus is the alternating load power supply, the 2nd power supply system accessible dc bus is the the DC load power supply, so the required electric energy of the DC load can obtain through the conversion that exchanges the direct current, has consequently avoided handing over the straight system's electric energy loss that results in of changing to a certain extent.