The invention provides a spraying waste gas magnetizing purification method and device. The spraying waste gas magnetizing purification method comprises the following steps that in the spraying waste gas collection process, paint mist particles in spraying waste gas are coated with nano soft magnetic powder to form magnetized paint mist particles; the magnetized paint mist particles are led into a magnetic separator to be collected; and the collected magnetized paint mist particles are dissolved through a solvent capable of dissolving the paint mist particles, meanwhile nano soft magnetic powder is recovered, and circulation is conducted in this way. The spraying waste gas magnetizing purification device comprises a magnetizer and a magnetic separation system. According to the spraying waste gas magnetizing purification method and device, the characteristic that the paint mist particles have viscosity is ingeniously utilized, the paint mist particles in the praying waste gas are magnetized by being wrapped with the soft magnetic nano powder, the surfaces of the paint mist particles are modified, and in this way, the viscosity of the paint mist particles is eliminated, the paint mist particles can also be adsorbed by an electromagnetic plate under the effect of a magnetic field, and the effect of filtering the paint mist particles is achieved through magnetic separation.