The invention discloses a treatment method for removing detergent in domestic wastewater. The treatment method includes: allowing the domestic wastewater containing the detergent to sequentially pass a preprocessing unit, a primary filter tank, a primary settling tank, a pH regulating tank, an ion-Hall effect separation tank, an aeration nitration tank, a biological nitrogen removal tank, a secondary settling tank, a purified water tank and the like. The treatment method has the advantages that the method creatively uses an electromagnetism induction phenomenon called Hall effect, when currents transmit in a wastewater tank in a way that the currents are vertical to an outer magnetic field, a carrier deflects, and an additional electric field is generated in the direction vertical to the currents and the magnetic field; as long as an electromagnet and an discharge electrode are respectively placed at appropriate positions to allow the magnetic induction line direction and the current direction to vertically pass the water tank along two horizontal directions, potential difference can be generated in the vertical direction of the water tank, the detergent ions in the waste water are allowed to move downwardly and be enriched at the bottom of the water tank to gradually form sludge, and accordingly the detergent is removed from the wastewater.