The invention relates to the technical field of material machining and discloses a mechanical-electromagnetic stirring device and method. The mechanical-electromagnetic stirring device comprises a stirring tank, a mechanical stirring system and an electromagnetic stirring system; the mechanical stirring system comprises a stirring spindle and a stirring blade; the electromagnetic stirring system comprises a coil assembly; and the coil assembly generates a traveling wave magnetic field in the stirring tank so as to drive melts located in a stirring stagnating zone and a stirring dead zone and melts of other zones to be exchanged. The mechanical-electromagnetic stirring method comprises the steps that the stirring tank is provided; the mechanical stirring system and the electromagnetic stirring system are arranged; metal matrix materials are poured into the stirring tank and heated till to be completely molten; the mechanical stirring system and the electromagnetic stirring system stir and mix the metal matrix materials inside the stirring tank; and reinforced phase powder is added into the stirring tank, and the mixture continues to be stirred. The mechanical-electromagnetic stirring device and method can ensure distribution uniformity of reinforced phases in the melts, so that composite materials with the high volume fraction of the reinforced phases are prepared.