Sewage treatment system for cold region

The utility model discloses a sewage treatment system for a cold region. The sewage treatment system comprises a sewage pretreatment device, an adjusting tank, a water distribution well, a CWSBR tank, a tail water treatment device and a sewage source heat pump heating system, wherein the sewage pretreatment device, the adjusting tank, the water distribution well, the CWSBR tank and the tail water treatment device are sequentially connected, and the sewage source heat pump heating system is connected between the adjusting tank and the tail water treatment device. The sewage source heat pump and the heat exchanger in the sewage source heat pump heating system are used for heating the inlet water of the sewage plant to 12-14 DEG C, so that a proper environment temperature is created for subsequent biochemical treatment, in addition, the tail water waste heat extraction unit is used for recycling waste heat after sewage treatment, the energy utilization efficiency is further improved, and the energy consumption i