Wastewater treatment system and method

The invention provides a wastewater treatment system and method.The system comprises a high-load carbonization/denitrification reaction tank, a secondary sedimentation tank, a one-stage anaerobic ammonia oxidation reactor, a nitrosation reactor and an anaerobic ammonia oxidation reactor which are sequentially connected through pipelines; the water inlet pipeline is connected with a water inlet of the high-load carbonization/denitrification reaction tank; and the water outlet pipeline is connected with a water outlet of the anaerobic ammonia oxidation reactor. When the method is applied to wastewater treatment, the removal rate of total nitrogen can be effectively increased, the final effluent quality is ensured to reach the standard, the aeration rate does not need to be strictly controlled, the complexity is low, the operation difficulty is small, control and implementation are easy, an advanced treatment process section does not need to be connected, an additional carbon source does not need to be added, an