The present invention discloses a continuous flow shortcut nitrification-anaerobic ammonium oxidation biological denitrification method based on granular sludge, and an apparatus. The method comprises: 1) carrying out sludge inoculation culture, and carrying out an active sludge adaptation period; 2) starting a shortcut nitrification-anaerobic ammonium oxidation reaction; 3) performing an anaerobic ammonium oxidation granular sludge formation and growth period; and 4) performing a stable operation period of a granular sludge continuous flow system. The apparatus comprises a water inlet tank, a bioreactor, a sedimentation tank and a hydraulic screen filter, wherein the water inlet tank, the bioreactor, the sedimentation tank and the hydraulic screen filter are sequentially communicated, the influent of the water inlet tank is communicated with high ammonia nitrogen wastewater, the effluent is communicated with the bioreactor, the concentrated sludge on the bottom of the sedimentation tank is communicated with the bioreactor through a sludge reflux pump, a fixation filler, a stirrer, a filtration screen and an aeration head communicated with an air compressor are arranged inside an anoxic reactor, the sedimentation tank is provided with a clear overflow port communicated with the hydraulic screen filter through a pipeline, the effluent of the hydraulic screen filter is the final effluent, and the retained granular sludge refluxes to the bioreactor.