The invention provides a microporous activating system for industrial waste Al2O3 microspheres and a processing method thereof. The system comprises an activating device and a waste liquid circulationutilization system. The activating device comprises an ash-blowing dust-collecting device, an impregnation activating module, and a transmission device. The transmission device is connected to the ash-blowing dust-collecting device and the impregnation activating module. The ash-blowing dust-collecting device is arranged in the material inlet side of the activating device. The impregnation activating module is arranged in the material outlet side of the activating device. The impregnation activating module comprises a thermal insulation device. In the thermal insulation device, an activatingtank and a drying device are arranged in sequence along the moving direction of the transmission device. The bottom of the activating tank is provided with an elevating device. The waste liquid outletof the activating tank is connected to the waste liquid circulation utilization system. The efficiency of regeneration of Al2O3 microspheres, which have been processed by microporous activation, is improved. Regenerated Al2O3 microspheres with good properties can be produced by the provided system and method.