Integrated wastewater treatment device and treatment method thereof

The invention discloses an integrated wastewater treatment device and a treatment method thereof. The device comprises an anoxic area, an aerobic area and a sedimentation area between the anoxic areaand the aerobic area, wherein the bottom of the anoxic area is connected with the aerobic area through a communicating pipe so that water treated in the anoxic area can overflow to the aerobic area for shortcut nitrification treatment; the aerobic area is provided with an aeration system; the anoxic area is connected with a mixed liquid backflow device so that shortcut nitrification wastewater canflow back to the anoxic area, and meanwhile, on the basis of a second air lift pump with which the aerobic area is provided, muddy water of the aerobic area is pumped into the sedimentation area; a sludge backflow opening is formed in the bottom of the sedimentation area, and is used for making sludge flow back to the anoxic area, and a water discharging opening is formed in the bottom of the sedimentation area, and is us