An apparatus and method for spiral polishing with electromagnetic abrasive has adopted the principle of electromagnetic and magnetic abrasive along with a lead screw to polish the inner or outer surface of a precise screw or a complicated part. The apparatus includes a clamp, a lead screw, a first electromagnet, and a second electromagnet assembled in an airtight space, wherein the airtight space is filled with magnetic abrasive which is driven by the rotation of the lead screw and the electromagnetic function to polish a processed part in a regular shape or in an irregular shape.