The invention belongs to the technical field of welding materials, and particularly relates to welding wire powder, flux-cored wire and preparation and application. The welding wire powder comprises,by mass, 15-18% of metal chromium, 3-5% of metal nickel, 6-8% of manganese metal, 0.6-1% of rare earth ferrosilicon, 2-4% of aluminum iron, 0.8%-1.5% of ferrotitanium, 25-28% of rutile, 1-2% of zirconsand, 6-9% of quartz, 3-5% of aluminum oxide, 3-5% of magnetite, 3-6% of potassium titanate, 1-2% of sodium fluoride, 3-4.5% of dehydrated potash feldspar, 0.15-0.3% of bismuth oxide, 0.5-1% of rareearth fluoride, and the balance iron powder. The invention further provides the flux-cored wire containing the powder. The flux-cored wire is good in welding process, small in splashing, good in spreading and fusing performance, stable in arc, easy to deslag, attractive in forming, and excellent in mechanical property.