Device and method for treating wastewater with low carbon nitrogen ratio

The invention discloses a device and a method for treating wastewater with a low carbon nitrogen ratio, and belongs to the technical field of sewage treatment. The device comprises a water inlet pump, a short-cut nitrification tank, a sedimentation tank, an intermediate storage tank and an integrated reactor, a first water outlet valve and a second water outlet valve are arranged at an outlet of the water inlet pump, and the short-cut nitrification tank is connected with the first water outlet valve; the sedimentation tank is connected with the short-cut nitrification tank, the middle storage tank is connected with a second water outlet valve and the sedimentation tank, and a short-cut denitrification lift pump is arranged at the bottom of the middle storage tank; the integrated reactor is connected with an outlet of the short-cut denitrification lift pump, and the integrated reactor is divided into a short-cut denitrification reaction zone, an anaerobic ammonia oxidation reaction zone and a settling zone fro