In a waste wire harness including electric wires each coated with a resin comprised of an olefin-based resin and magnesium hydroxide as a fire retardant, and including accompanied members having at least one of terminals, connectors, various kind of boxes such as junction boxes and fuse boxes, tapes, tubes, grommets, wiring clips, and protectors, a method for recycling the waste wire harness includes a step of removing the accompanied members from the waste wire harness, a step of crushing the waste wire harness after removing the accompanied members to obtain crushed particles, a step of incinerating the crushed particles to produce incinerated ash, a step of converting a magnesium compound contained in the incinerated ash into magnesium hydroxide, and a step of collecting the magnesium hydroxide.